---
title: How to Select the Right RTD Sensing Element for Your Application
description: Learn how to select the right RTD sensing element for your application, focusing on accuracy, construction, wiring and compliance with industry standards.
image: https://blog.ashcroft.com/hubfs/RTD_Element_Ohm_BLOG_V1.jpg
---

[Skip to main content](https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application#maincontent)

 Select Region

- [US & Canada](https://ashcroft.com)
- [Europe](https://ashcroft.eu/)
- [China](http://www.ashcroft.com.cn/)
- [Mexico & Central America](http://www.ashcroft.com.mx/)
- [South America](https://ashcroftsudamericana.com/)
- [Brazil](https://ashcroft.com.br/)

 Login

- [Distributor Extranet](https://extranet.ashcroft.com/)
- [Product Configurator](https://www.ashcroft.com/my-account/)

[Careers](https://www.ashcroft.com/careers)

[Contact](https://www.ashcroft.com/contact/)

[![ashcroft-logo-lg-2](https://blog.ashcroft.com/hs-fs/hubfs/ashcroft-logo-lg-2.png?width=261&height=60&name=ashcroft-logo-lg-2.png) ![ashcroft-logo-white](https://blog.ashcroft.com/hubfs/assets/images/ashcroft-logo-white.svg)](https://www.ashcroft.com/)

 Products

 Pressure Instruments

- [Pressure Gauges](https://www.ashcroft.com/products/pressure/pressure-gauges)
- [Pressure Switches](https://www.ashcroft.com/products/pressure/pressure-switches)
- [Pressure Sensors (Transducers/Transmitters)](https://www.ashcroft.com/products/pressure/pressure-sensors)
- [Diaphragm Seals-Isolators](https://www.ashcroft.com/products/pressure/diaphragm-seals-and-isolators)
- [Accessories](https://www.ashcroft.com/products/pressure/accessories)
- [SMART Transmitter Assemblies](https://www.ashcroft.com/products/pressure/smart-transmitter-assemblies)

 Temperature Instruments

- [Thermometers](https://www.ashcroft.com/products/temperature/thermometers)
- [Thermowells](https://www.ashcroft.com/products/temperature/thermowells)
- [Temperature Switches](https://www.ashcroft.com/products/temperature/temperature-switches)
- [RTDs](https://www.ashcroft.com/products/temperature/rtds)
- [Thermocouples](https://www.ashcroft.com/products/temperature/thermocouples)
- [Temperature Transmitters](https://www.ashcroft.com/products/temperature/temperature-transmitters/)
- [MultiPoint Temperature Sensors](https://www.ashcroft.com/products/temperature/multipoint-temperature-sensors/)
- [OEM Temperature Sensors](https://www.ashcroft.com/products/temperature/oem-temperature-sensors)

 Test Instruments

- [Calibrators](https://www.ashcroft.com/products/test-instruments/calibrators/)
- [Hand Pumps-Controllers](https://www.ashcroft.com/products/test-instruments/hand-pumps-and-controllers/)
- [Hydraulic Testers](https://www.ashcroft.com/products/test-instruments/hydraulic-testers/)
- [Test Gauges](https://www.ashcroft.com/products/test-instruments/test-gauges/)

 Helpful Tools

- [Product Documentation](https://www.ashcroft.com/learn/product-documentation/)
- [Product & Quality Certifications](https://www.ashcroft.com/about/quality-certifications/)
- [Material Selector & Corrosion Guide](https://www.ashcroft.com/webtools/materialselector/)
- [Unit Converter](https://www.ashcroft.com/webtools/calculatoruom/)
- [Wake Frequency Calculator](https://www.ashcroft.com/webtools/calculatorwf/)
- [FAQs](https://www.ashcroft.com/faq/)

 Keep your critical equipment and processes running with reliable pressure and temperature measurements.

[Configure Product Part Number](https://www.ashcroft.com/product-configurator) [Get a Quote](https://www.ashcroft.com/quote)

 Industries

 Process Industry Overview

- [Solutions for the Process Industry](https://www.ashcroft.com/solutions/process-industry-instrumentation)
- [Large Projects/EPC](https://www.ashcroft.com/solutions/process-industry-instrumentation/engineering-procurement-construction-large-projects/)
- [Critical Application Solution Experts](https://www.ashcroft.com/solutions/process-industry-instrumentation/critical-application-solution-experts/)
- [Distributor Locator](https://www.ashcroft.com/ashcroft-distributors/)

 Process Industry Solutions

- [Chemical & Petrochemical](https://www.ashcroft.com/solutions/process-industry-instrumentation/chemical-process-instrumentation/)
- [Food & Beverage](https://www.ashcroft.com/solutions/process-industry-instrumentation-sensors/food-beverage/)
- [Metals & Minerals](https://www.ashcroft.com/solutions/process-industry-instrumentation/mining-instruments/)
- [Oil & Gas](https://www.ashcroft.com/solutions/process-industry-instrumentation/oil-gas-instrumentation/)
- [Pharmaceutical & Biotech](https://www.ashcroft.com/solutions/process-industry-instrumentation/pharmaceutical-and-biotechnology-application-solutions/)
- [Power](https://www.ashcroft.com/solutions/process-industry-instrumentation/power-plant-instrumentation/)
- [Water & Wastewater](https://www.ashcroft.com/solutions/process-industry-instrumentation/instruments-used-in-water-treatment-plant/)

 Industrial/OEM Markets Overview

- [Solutions for Industrial OEM](https://www.ashcroft.com/solutions/industrial-oem/)
- [Custom Engineered Solutions (CES)](https://www.ashcroft.com/solutions/industrial-oem-custom-engineered-solutions/)

 Industrial/OEM Markets

- [HVAC/R](https://www.ashcroft.com/solutions/industrial-oem/hvac-refrigeration-equipment/)
- [Hydrogen & Alternative Energu](https://www.ashcroft.com/solutions/industrial-oem/hydrogen-alternative-energy/)
- [Industrial Equipment Manufacturer](https://www.ashcroft.com/solutions/industrial-oem/industrial-equipment-manufacturer-supplier/)
- [Medical Health & Safety](https://www.ashcroft.com/solutions/industrial-oem/medical-biotechnology-instruments/)
- [Process Equipment Manufacturer](https://www.ashcroft.com/solutions/industrial-oem/process-equipment-manufacturer/)
- [Semiconductor](https://www.ashcroft.com/solutions/industrial-oem/ultra-high-purity-gas-delivery-semiconductor-manufacturing/)
- [Vehicles](https://www.ashcroft.com/solutions/industrial-oem/vehicles-working-machines/)

 Resources

- [Product Documentations](https://www.ashcroft.com/learn/product-documentation/)
- [Educational Resources](https://www.ashcroft.com/learn/resource-center/)

 About

- [About](https://www.ashcroft.com/about/)
- [Corporate Responsibility](https://www.ashcroft.com/about/corporate-responsibility/)
- [Code of Conduct](https://www.ashcroft.com/about/corporate-responsibility/code-of-conduct/)
- [Trade Compliance](https://www.ashcroft.com/about/corporate-responsibility/trade-compliance/)
- [Product Stewardship](https://www.ashcroft.com/about/corporate-responsibility/product-stewardship/)
- [Company News & Events](https://www.ashcroft.com/news-events/)
- [Leadership Team](https://www.ashcroft.com/about/leadership/)
- [Brands & Trademarks](https://www.ashcroft.com/about/brands-trademarks/)
- [Careers](https://www.ashcroft.com/careers/)

[Get a Quote](https://sales.ashcroft.com/quote)

 Products

 Products

[Pressure Instruments](https://www.ashcroft.com)

 Pressure Instruments

[Pressure Gauges](https://www.ashcroft.com/products/pressure/pressure-gauges)

[Pressure Switches](https://www.ashcroft.com/products/pressure/pressure-switches)

[Pressure Sensors (Transducers/Transmitters)](https://www.ashcroft.com/products/pressure/pressure-sensors)

[Diaphragm Seals-Isolators](https://www.ashcroft.com/products/pressure/diaphragm-seals-and-isolators)

[Accessories](https://www.ashcroft.com/products/pressure/accessories)

[SMART Transmitter Assemblies](https://www.ashcroft.com/products/pressure/smart-transmitter-assemblies)

[Temperature Instruments](https://www.ashcroft.com)

 Temperature Instruments

[Thermometers](https://www.ashcroft.com/products/temperature/thermometers)

[Thermowells](https://www.ashcroft.com/products/temperature/thermowells)

[Temperature Switches](https://www.ashcroft.com/products/temperature/temperature-switches)

[RTDs](https://www.ashcroft.com/products/temperature/rtds)

[Thermocouples](https://www.ashcroft.com/products/temperature/thermocouples)

[Temperature Transmitters](https://www.ashcroft.com/products/temperature/temperature-transmitters/)

[MultiPoint Temperature Sensors](https://www.ashcroft.com/products/temperature/multipoint-temperature-sensors/)

[OEM Temperature Sensors](https://www.ashcroft.com/products/temperature/oem-temperature-sensors)

[Test Instruments](https://www.impactplus.com)

 Test Instruments

[Calibrators](https://www.ashcroft.com/products/test-instruments/calibrators/)

[Hand Pumps-Controllers](https://www.ashcroft.com/products/test-instruments/hand-pumps-and-controllers/)

[Hydraulic Testers](https://www.ashcroft.com/products/test-instruments/hydraulic-testers/)

[Test Gauges](https://www.ashcroft.com/products/test-instruments/test-gauges/)

[Helpful Tools](https://www.impactplus.com)

 Helpful Tools

[Product Documentation](https://www.ashcroft.com/learn/product-documentation/)

[Product & Quality Certifications](https://www.ashcroft.com/about/quality-certifications/)

[Material Selector & Corrosion Guide](https://www.ashcroft.com/webtools/materialselector/)

[Unit Converter](https://www.ashcroft.com/webtools/calculatoruom/)

[Wake Frequency Calculator](https://www.ashcroft.com/webtools/calculatorwf/)

[FAQs](https://www.ashcroft.com/faq/)

 Industries

 Industries

[Process Industry Overview](https://www.impactplus.com)

 Process Industry Overview

[Solutions for the Process Industry](https://www.ashcroft.com/solutions/process-industry-instrumentation)

[Large Projects/EPC](https://www.ashcroft.com/solutions/process-industry-instrumentation/engineering-procurement-construction-large-projects/)

[Critical Application Solution Experts](https://www.ashcroft.com/solutions/process-industry-instrumentation/critical-application-solution-experts/)

[Distributor Locator](https://www.ashcroft.com/ashcroft-distributors/)

[Process Industry Solutions](https://www.impactplus.com)

 Process Industry Solutions

[Chemical & Petrochemical](https://www.ashcroft.com/solutions/process-industry-instrumentation/chemical-process-instrumentation/)

[Food & Beverage](https://www.ashcroft.com/solutions/process-industry-instrumentation-sensors/food-beverage/)

[Metals & Minerals](https://www.ashcroft.com/solutions/process-industry-instrumentation/mining-instruments/)

[Oil & Gas](https://www.ashcroft.com/solutions/process-industry-instrumentation/oil-gas-instrumentation/)

[Pharmaceutical & Biotech](https://www.ashcroft.com/solutions/process-industry-instrumentation/pharmaceutical-and-biotechnology-application-solutions/)

[Power](https://www.ashcroft.com/solutions/process-industry-instrumentation/power-plant-instrumentation/)

[Water & Wastewater](https://www.ashcroft.com/solutions/process-industry-instrumentation/instruments-used-in-water-treatment-plant/)

[Industrial/OEM Markets Overview](https://www.impactplus.com)

 Industrial/OEM Markets Overview

[Solutions for Industrial OEM](https://www.ashcroft.com/solutions/industrial-oem/)

[Custom Engineered Solutions (CES)](https://www.ashcroft.com/solutions/industrial-oem-custom-engineered-solutions/)

[Industrial/OEM Markets](https://www.impactplus.com)

 Industrial/OEM Markets

[HVAC/R](https://www.ashcroft.com/solutions/industrial-oem/hvac-refrigeration-equipment/)

[Hydrogen & Alternative Energu](https://www.ashcroft.com/solutions/industrial-oem/hydrogen-alternative-energy/)

[Industrial Equipment Manufacturer](https://www.ashcroft.com/solutions/industrial-oem/industrial-equipment-manufacturer-supplier/)

[Medical Health & Safety](https://www.ashcroft.com/solutions/industrial-oem/medical-biotechnology-instruments/)

[Process Equipment Manufacturer](https://www.ashcroft.com/solutions/industrial-oem/process-equipment-manufacturer/)

[Semiconductor](https://www.ashcroft.com/solutions/industrial-oem/ultra-high-purity-gas-delivery-semiconductor-manufacturing/)

[Vehicles](https://www.ashcroft.com/solutions/industrial-oem/vehicles-working-machines/)

 Resources

 Resources

[Product Documentations](https://www.ashcroft.com/learn/product-documentation/)

[Educational Resources](https://www.ashcroft.com/learn/resource-center/)

 About

 About

[About](https://www.ashcroft.com/about/)

[Corporate Responsibility](https://www.ashcroft.com/about/corporate-responsibility/)

[Code of Conduct](https://www.ashcroft.com/about/corporate-responsibility/code-of-conduct/)

[Trade Compliance](https://www.ashcroft.com/about/corporate-responsibility/trade-compliance/)

[Product Stewardship](https://www.ashcroft.com/about/corporate-responsibility/product-stewardship/)

[Company News & Events](https://www.ashcroft.com/news-events/)

[Leadership Team](https://www.ashcroft.com/about/leadership/)

[Brands & Trademarks](https://www.ashcroft.com/about/brands-trademarks/)

[Careers](https://www.ashcroft.com/careers/)

 Select Region

 Select Region

[US & Canada](https://ashcroft.com)

[Europe](https://ashcroft.eu/)

[China](http://www.ashcroft.com.cn/)

[Mexico & Central America](http://www.ashcroft.com.mx/)

[South America](https://ashcroftsudamericana.com/)

[Brazil](https://ashcroft.com.br/)

 Login

 Login

[Distributor Extranet](https://extranet.ashcroft.com/)

[Product Configurator](https://www.ashcroft.com/my-account/)

[Careers](https://www.ashcroft.com/careers)

[Contact](https://www.ashcroft.com/contact/)

[Get a Quote](https://sales.ashcroft.com/quote)

[«  View All Articles](https://blog.ashcroft.com/)

![Marco Santoro - Business Development Leader - Europe, Temperature & Pressure's headshot](https://blog.ashcroft.com/hs-fs/hubfs/Marco%20Santoro.jpg?width=50&height=50&name=Marco%20Santoro.jpg)

**By:** [Marco Santoro - Business Development Leader - Europe](https://blog.ashcroft.com/author/marco-santoro-business-development-leader-temperature-solutions-europe)   
 Temperature & Pressure

**Published on:**   
 August 11th, 2025

**Topics:**

[RTD](https://blog.ashcroft.com/topic/rtd) [temperature sensor](https://blog.ashcroft.com/topic/temperature-sensor) [pharmaceutical and biotechnology](https://blog.ashcroft.com/topic/pharmaceutical-and-biotechnology) [temperature measurement](https://blog.ashcroft.com/topic/temperature-measurement) [HVAC](https://blog.ashcroft.com/topic/hvac)

**Share:**

<https://www.facebook.com/sharer/sharer.php?u=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://twitter.com/intent/tweet?text=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://www.linkedin.com/shareArticle?url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application&title=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&summary=Learn+how+to+select+the+right+RTD+sensing+element+for+your+application%2C+focusing+on+accuracy%2C+construction%2C+wiring+and+compliance+with+industry+standards.> [mailto:?subject=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&body=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application](mailto:?subject=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&body=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application)

 Subscribe

 Never miss a blog post!

 Subscribe now and get the latest blog posts delivered straight to your inbox.

# How to Select the Right RTD Sensing Element for Your Application

 Print/Save as PDF

![Marco Santoro - Business Development Leader - Europe, Temperature & Pressure's headshot](https://blog.ashcroft.com/hs-fs/hubfs/Marco%20Santoro.jpg?width=50&height=50&name=Marco%20Santoro.jpg)

**By:** [Marco Santoro - Business Development Leader - Europe](https://blog.ashcroft.com/author/marco-santoro-business-development-leader-temperature-solutions-europe)   
 Temperature & Pressure

**Published on:**   
 August 11th, 2025

**Topics:**

[RTD](https://blog.ashcroft.com/topic/rtd) [temperature sensor](https://blog.ashcroft.com/topic/temperature-sensor) [pharmaceutical and biotechnology](https://blog.ashcroft.com/topic/pharmaceutical-and-biotechnology) [temperature measurement](https://blog.ashcroft.com/topic/temperature-measurement) [HVAC](https://blog.ashcroft.com/topic/hvac)

**Share:**

<https://www.facebook.com/sharer/sharer.php?u=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://twitter.com/intent/tweet?text=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://www.linkedin.com/shareArticle?url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application&title=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&summary=Learn+how+to+select+the+right+RTD+sensing+element+for+your+application%2C+focusing+on+accuracy%2C+construction%2C+wiring+and+compliance+with+industry+standards.> [mailto:?subject=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&body=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application](mailto:?subject=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&body=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application)

![](https://blog.ashcroft.com/hs-fs/hubfs/RTD_Element_Ohm_BLOG_V1.jpg?width=1600&height=534&name=RTD_Element_Ohm_BLOG_V1.jpg)

In any process where accurate temperature monitoring is critical, from power generation and HVAC systems to food processing and pharmaceutical manufacturing, Resistance Temperature Detectors (RTDs) are one of the most trusted sensor technologies. Selecting the right RTD element is essential for achieving high performance, long-term stability and compliance with industry standards.

Ashcroft, a global leader in temperature and pressure instrumentation, has decades of experience helping customers specify, install and calibrate RTDs in demanding environments. 

Read this article to learn about RTD sensing elements, how they work and how to select the right element based on industry requirements, construction, accuracy, wiring and environmental factors.

## What is an RTD Sensing Element

An **RTD element** is the core sensing component of an RTD sensor. It's typically made from platinum and is designed to change its **electrical resistance** in a predictable way as temperature changes. The resistance is measured by a monitoring device, such as a transmitter or controller, and converted into a temperature reading.

The most common RTD elements include:

- **Pt100**: 100 ohms at 0 °C  (32 °F)
- **Pt1000**: 1000 ohms at 0 °C  (32 °F)

Ohm is the unit of measurement that is often represented with the symbol Ω.

*Figure 1. OHM Unit of Measure*

![RTD Resistance to Temperature Relationship](https://blog.ashcroft.com/hs-fs/hubfs/RTD%20Resistance%20to%20Temperature%20Relationship.png?width=281&height=208&name=RTD%20Resistance%20to%20Temperature%20Relationship.png)

## Built to Meet Strict International Performance Standards

Before discussing sensing element construction types or wiring methods, it’s important to understand the **standard that governs RTD performance**: **IEC 60751**. This international standard defines:

- The temperature coefficient of resistance (typically 0.00385 Ω/Ω/°C for platinum)
- Tolerance classes (e.g., Class B, A, AA)
- Resistance-temperature relationship curves (commonly referred to as "385 curves")
- Construction criteria for thin-film and wire-wound elements

Compliance with IEC 60751 ensures your RTD sensor will work predictably and interchangeably with other IEC-compliant components, such as transmitters, controllers and calibrators.

## The Sensing Principle of RTDs

The RTD sensing principle is simple: **as temperature increases, the electrical resistance of the platinum element increases** in a well-defined, mostly linear way. For instance:

- A Pt100 element has 100.0 ohms at 0 °C.
- At 100 °C (212 °F) , it typically has 138.5 ohms, yielding a slope of 0.385 Ω/°C.

Because of this predictable behavior, RTDs are highly repeatable and offer exceptional measurement accuracy, especially when compared to thermocouples, which are more prone to drift and nonlinearities.

## Types of RTD Elements: Wire-Wound vs. Thin-Film

RTD elements are built in different ways to meet varying performance needs. The two most common construction types are:

### **1. Wire-Wound RTD Elements**

- Made with a fine coil of platinum wire wound around a **ceramic or glass** core.
- Offers the **widest temperature range**: –200 °C to +850 °C (–328 °F to +1562 °F). 
- **Highest accuracy and long-term stability**, but generally more expensive and slower in response.
- Ideal for lab applications, aerospace, and high-precision process monitoring.

*Figure 2: Wire Round Sensing Element*

![wire wound](https://blog.ashcroft.com/hs-fs/hubfs/wire%20wound.png?width=320&height=285&name=wire%20wound.png)  
**2. Thin-Film RTD Elements**

- Platinum is deposited in a zig-zag pattern on a **ceramic substrate**, then protected with a glass or epoxy coating.
- Compact and cost-effective, with fast response times.
- Typical range: –50 °C to +400 °C (–58 °F to +752 °F).
- Used extensively in OEM sensors and industrial automation.

*Figure 3. Thin Film Sensing Element*

![Thin Film Sensing Element-1](https://blog.ashcroft.com/hs-fs/hubfs/Thin%20Film%20Sensing%20Element-1.png?width=277&height=177&name=Thin%20Film%20Sensing%20Element-1.png)  
Choosing the right construction depends on your temperature range, durability needs and cost constraints.

## Understanding RTD Accuracy and Tolerance Classes

Tolerance classes define how closely an RTD element’s output aligns with the ideal resistance-temperature curve. The tighter the class, the better the accuracy, but also the higher the cost and manufacturing complexity.

*Figure 4. RTD Accuracy and Tolerance Classes (per IEC 60751)*

*![RTD Element Tolerance and Temp](https://blog.ashcroft.com/hs-fs/hubfs/RTD%20Element%20Tolerance%20and%20Temp.png?width=656&height=159&name=RTD%20Element%20Tolerance%20and%20Temp.png)*

For regulated industries like pharmaceuticals or food, **Class AA** is often required. For general process control, Class A or B may suffice.

## PT100 vs. PT1000: Which Resistance Value is Right?

RTDs are most commonly available in **Pt100** and **Pt1000** variants.

*Figure 5. Two Pt100 and Pt1000 Variants *

*![RTD Element OHM Variance](https://blog.ashcroft.com/hs-fs/hubfs/RTD%20Element%20OHM%20Variance.png?width=650&height=134&name=RTD%20Element%20OHM%20Variance.png)*

Because Pt1000 elements generate a larger voltage drop, they are less impacted by lead wire resistance, making them ideal for **2-wire configurations** and long-distance installations.

## RTD Wiring Configurations: 2-, 3-, or 4-Wire?

The wiring method you choose for your RTD installation has a direct effect on measurement accuracy, particularly with lower resistance types like Pt100. There are three primary wiring configurations for RTDs:

- **The 2-wire RTD**. This is the most straightforward configuration, using a single lead wire from each end of the sensing element to the monitoring device. It is also the least accurate, as the total resistance measured includes both the element and the lead wires.
- **The 3-wire RTD**.By far,  the most common circuit design for RTDs used in industrial processes. This configuration includes two wires, one side of the sensing element and one wire connected to the other side. This arrangement nulls the lead resistance of the two wires connected to the side of the element, increasing the measurement accuracy, so it is well suited for process applications.
- **The 4-wire RTD**. This configuration offers the highest level of accuracy. The 4-wire circuit connects two wires to each end of the sensor element, fully eliminating the influence of lead wire resistance from the temperature reading. It is more complex and costly than the 2-wire and 3-wire options, but is ideal for applications demanding the highest precision.

*Figure 6. RTD Wiring Types*

![RTD Element Wiring Types](https://blog.ashcroft.com/hs-fs/hubfs/RTD%20Element%20Wiring%20Types.png?width=609&height=115&name=RTD%20Element%20Wiring%20Types.png)

## Key Selection Criteria: Match Element to Environment

When selecting an RTD element, keep these **application-driven factors** in mind:

![RTD Selection Considerations](https://blog.ashcroft.com/hs-fs/hubfs/RTD%20Selection%20Considerations.png?width=614&height=214&name=RTD%20Selection%20Considerations.png)

**Housing Compatibility and RTD Assemblies**

RTD elements don’t operate alone. They’re embedded into **protective housings and probes** that suit the environment. Ashcroft offers a range of assemblies such as:

- [S81 RTD Temperature Probe:](https://www.ashcroft.com/products/temperature/s81-rtd-temperature-probe/) Made with MI cables and is designed for high-vibration and industrial use. 
- [The S50 Industrial RTD:](https://www.ashcroft.com/products/temperature/s50-industrial-rtd/) Made with MI cables, this instrument is designed to work with thermowells and is and is well suited for OEM applications, remote monitoring, hazardous locations, and extreme service environments. 

Assemblies must match not only the process conditions but also the wiring method and installation type (e.g., direct mount, remote, sanitary, threaded, or flanged).

## Ready to Learn More?

Now you understand why selecting the right RTD sensing element involves more than simply picking a resistance value. It is also about matching your system’s needs for accuracy, speed, durability and compliance. If you want to deepen your knowledge further, we have several related articles about temperature products: 

- [Which thermocouple lead wire is best for my application?](https://blog.ashcroft.com/which-thermocouple-leadwire-is-best)
- [How an RTD works](https://blog.ashcroft.com/how-an-rtd-works)
- <https://blog.ashcroft.com/bimetal-thermometer-cost>[When to use an RTD or Thermocouple](https://blog.ashcroft.com/rtd-vs-thermocouple-temperature-sensor)

In the meantime, [download our guide](https://www.ashcroft.com/learn/product-documentation?pageNumber=1&search=RTD&sortType=date&sortOrder=DESC&content_type=31) to learn more about Ashcroft's temperature measurement solutions. 

[![New call-to-action](https://no-cache.hubspot.com/cta/default/4021582/c81b75cc-efe3-4427-a0d5-bf410e9b3cd4.png)](https://cta-redirect.hubspot.com/cta/redirect/4021582/c81b75cc-efe3-4427-a0d5-bf410e9b3cd4)

<https://blog.ashcroft.com/author/marco-santoro-business-development-leader-temperature-solutions-europe>

[Marco Santoro - Business Development Leader - Europe, Temperature & Pressure](https://blog.ashcroft.com/author/marco-santoro-business-development-leader-temperature-solutions-europe)

Marco joined Ashcroft in 2021 as the Business Development Manager responsible for selling the company’s temperature instruments in Europe. In 2025, Marco was promoted to the position of Business Development Leader for both Temperature and Pressure instrumentation, handling all strategic aspects of bringing products to market throughout European countries.

 Connect: 

<https://www.linkedin.com/in/marcosantoroms/>

 Topics:

[RTD](https://blog.ashcroft.com/topic/rtd)

[temperature sensor](https://blog.ashcroft.com/topic/temperature-sensor)

[pharmaceutical and biotechnology](https://blog.ashcroft.com/topic/pharmaceutical-and-biotechnology)

[temperature measurement](https://blog.ashcroft.com/topic/temperature-measurement)

[HVAC](https://blog.ashcroft.com/topic/hvac)

 Don't forget to share this post:

<https://www.facebook.com/sharer/sharer.php?u=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://www.linkedin.com/shareArticle?url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application&title=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&summary=Learn+how+to+select+the+right+RTD+sensing+element+for+your+application%2C+focusing+on+accuracy%2C+construction%2C+wiring+and+compliance+with+industry+standards.> <https://twitter.com/intent/tweet?text=How+to+Select+the+Right+RTD+Sensing+Element+for+Your+Application&url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application> <https://pinterest.com/pin/create/button/?url=https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application&media=https://4021582.fs1.hubspotusercontent-na1.net/hubfs/4021582/RTD_Element_Ohm_BLOG_V1.jpg&description=Learn+how+to+select+the+right+RTD+sensing+element+for+your+application%2C+focusing+on+accuracy%2C+construction%2C+wiring+and+compliance+with+industry+standards.>

## Related Articles

### [![](https://blog.ashcroft.com/hs-fs/hubfs/SteamApplic_BLOG.jpg?width=1600&height=534&name=SteamApplic_BLOG.jpg) How to Choose the Right Temperature Instrument for Steam Applications August , 2026|5 min. read](https://blog.ashcroft.com/temperature-instrument-for-steam-applications)

### [![Reasons temperature sensors fail](https://blog.ashcroft.com/hs-fs/hubfs/TempSensorFail_BLOG.jpg?width=1600&height=534&name=TempSensorFail_BLOG.jpg) What Causes Temperature Sensors to Fail? June , 2026|3 min. read](https://blog.ashcroft.com/what-causes-temperature-sensors-to-fail)

### [![Important features of an RTD and Thermocouple](https://blog.ashcroft.com/hs-fs/hubfs/RTD-TC_Features_BLOG_V2.jpg?width=1600&height=534&name=RTD-TC_Features_BLOG_V2.jpg) What Are Important Features of Temperature Sensors? April , 2026|4 min. read](https://blog.ashcroft.com/what-are-important-features-of-temperature-sensors)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/BimetalTherm_BLOG__TempTues.jpg?width=1600&height=534&name=BimetalTherm_BLOG__TempTues.jpg) Choosing a Bimetal Thermometer: 5 Factors to Consider March , 2026|4 min. read](https://blog.ashcroft.com/choosing-a-bimetal-thermometer)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/SaddleConnect_BLOG_V1.jpg?width=1600&height=534&name=SaddleConnect_BLOG_V1.jpg) Why Use a Saddle Seal in Process Applications? January , 2026|4 min. read](https://blog.ashcroft.com/why-use-a-saddle-connection-in-pressure-gauge-applications)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/FlushConnection_1032_BLOG.jpg?width=1600&height=534&name=FlushConnection_1032_BLOG.jpg) Why Use a Flush Connection in Sanitary Processes? November , 2025|4 min. read](https://blog.ashcroft.com/why-use-a-flush-connection-in-sanitary-processes)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost-ReviewRTD_TC_BLOG_V1.jpg?width=1600&height=534&name=Repost-ReviewRTD_TC_BLOG_V1.jpg) Product Review: RTDs and Thermocouples October , 2025|3 min. read](https://blog.ashcroft.com/product-review-rtds-and-thermocouples)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost-AccurateHVAC_BLOG_V1.jpg?width=1600&height=534&name=Repost-AccurateHVAC_BLOG_V1.jpg) How Accurate Are Your HVAC  Pressure Sensors? October , 2025|4 min. read](https://blog.ashcroft.com/how-accurate-are-your-hvac-pressure-instruments)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost_1032_1033_BLOG_V1.jpg?width=1600&height=534&name=Repost_1032_1033_BLOG_V1.jpg) Product Review: 1032 & 1033 Sanitary Pressure Gauges September , 2025|3 min. read](https://blog.ashcroft.com/product-review-1032-sanitary-pressure-gauge)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/PrSensors_BLOG_V2.jpg?width=1600&height=534&name=PrSensors_BLOG_V2.jpg) Choosing the Right Pressure Sensor: 5 Factors to Consider August , 2025|4 min. read](https://blog.ashcroft.com/choosing-the-right-pressure-sensor)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Tri-Clamp_BLOG_V2.jpg?width=1600&height=534&name=Tri-Clamp_BLOG_V2.jpg) Why Use Tri-Clamp Fittings for Hygienic Applications? August , 2025|4 min. read](https://blog.ashcroft.com/why-use-tri-clamp-fittings-for-hygienic-applications)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost_8009S_Bayonet_BLOG_V1.jpg?width=1600&height=534&name=Repost_8009S_Bayonet_BLOG_V1.jpg) Product Review: Stainless Steel Pressure Gauge with Removable Bayonet Ring August , 2025|3 min. read](https://blog.ashcroft.com/8009s-pressure-gauge-with-bayonet-ring)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Types_TW_BLOG_TempTues.jpg?width=1600&height=534&name=Types_TW_BLOG_TempTues.jpg) When to Use Straight, Tapered or Stepped Thermowells August , 2025|4 min. read](https://blog.ashcroft.com/when-to-use-straight-tapered-or-stepped-thermowells)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost_TubeLength_BLOG_V1.jpg?width=1600&height=534&name=Repost_TubeLength_BLOG_V1.jpg) Can Pressure Tubing Length Affect My Low-Pressure Transducer? August , 2025|3 min. read](https://blog.ashcroft.com/pressure-tubing-length-affect-transducer)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/TC%26RTD-Ext_BLOG_V1.jpg?width=1600&height=534&name=TC%26RTD-Ext_BLOG_V1.jpg) Thermocouple and RTD Lead Wire Extensions: What You Need To Know July , 2025|3 min. read](https://blog.ashcroft.com/thermocouple-and-rtd-extensions-what-you-need-to-know)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/IndustRefr_BLOG_V3.jpg?width=1600&height=534&name=IndustRefr_BLOG_V3.jpg) Temperature Sensors for Industrial Refrigeration Ammonia Compressors July , 2025|4 min. read](https://blog.ashcroft.com/temperature-sensors-for-refrigeration-ammonia-compressors)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Repost-RTDvsTC_BLOG_V3.jpg?width=1600&height=534&name=Repost-RTDvsTC_BLOG_V3.jpg) When to Use an RTD vs. a Thermocouple Temperature Sensor July , 2025|3 min. read](https://blog.ashcroft.com/rtd-vs-thermocouple-temperature-sensor)

### [![Cost of temperature sensors](https://blog.ashcroft.com/hs-fs/hubfs/TempSenseCost_BLOG_TempTues.jpg?width=1600&height=534&name=TempSenseCost_BLOG_TempTues.jpg) How Much Do Temperature Sensors Cost? June , 2025|4 min. read](https://blog.ashcroft.com/temperature-sensor-cost)

### [![Pressure Instruments for Pharmaceutical and Biotechnology Applications](https://blog.ashcroft.com/hs-fs/hubfs/Repost_Pharma_Biotech_BLOG_V2.jpg?width=1600&height=534&name=Repost_Pharma_Biotech_BLOG_V2.jpg) Pressure Instruments for Pharmaceutical and Biotechnology Applications June , 2025|4 min. read](https://blog.ashcroft.com/best-pressure-instruments-for-pharmaceutical-and-biotechnology-applications)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/CleanInPlace_BLOG_V3.jpg?width=1600&height=534&name=CleanInPlace_BLOG_V3.jpg) CIP, SIP, Autoclaving: A Comparative Review of Pressure Gauge Cleaning Technologies May , 2025|5 min. read](https://blog.ashcroft.com/cip-sip-autoclaving-cleaning-technologies-for-pressure-gauges)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/XproofRTD_TC_BLOG_V2.jpg?width=1600&height=534&name=XproofRTD_TC_BLOG_V2.jpg) Why Fully Certified Thermocouples and RTDs are Critical for Hazardous Locations March , 2025|3 min. read](https://blog.ashcroft.com/rtd-thermocouple-certification-for-hazardous-locations)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Basics.BLOG_1-15-25.jpg?width=1600&height=534&name=Basics.BLOG_1-15-25.jpg) What is a Thermocouple January , 2025|3 min. read](https://blog.ashcroft.com/what-is-a-thermocouple)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Basics.BLOG_1-08-25.jpg?width=6667&height=2225&name=Basics.BLOG_1-08-25.jpg) What is an RTD? January , 2025|3 min. read](https://blog.ashcroft.com/what-is-an-rtd)

### [![](https://blog.ashcroft.com/hs-fs/hubfs/Basics.BLOG_12-18-24.jpg?width=1600&height=534&name=Basics.BLOG_12-18-24.jpg) Which RTD & Thermocouple Lag Extension is right for me? December , 2024|3 min. read](https://blog.ashcroft.com/rtd-thermocouple-lag-types)

![https://f.hubspotusercontent30.net/hubfs/4021582/assets/images/ashcroft-logo-white.svg](https://blog.ashcroft.com/hubfs/assets/images/ashcroft-logo-white.svg)

250 East Main Street  
Stratford, CT 06614  
[800.328.8258](tel:+1800.328.8258)

[Contact](https://www.ashcroft.com/contact/)

[Learning Center](https://www.ashcroft.com/learn/resource-center) [Blog](https://blog.ashcroft.com/) [Subscribe to Blog](https://sales.ashcroft.com/ashcroft-blog-subscribe)

[Facebook](https://www.facebook.com/AshcroftInc) [Instagram](https://www.instagram.com/ashcroftinc/) [LinkedIn](https://www.linkedin.com/company/ashcroft-inc-/) [YouTube](https://www.youtube.com/user/AshcroftInc)

[PRODUCTS](https://www.ashcroft.com/products)

- [Pressure Instruments](https://www.ashcroft.com/products/#pressure)
- [Temperature Instruments](https://www.ashcroft.com/products/#temperature)
- [Test Instruments](https://www.ashcroft.com/products/#test-instruments)
- [Product Configurator](https://www.ashcroft.com/product-configurator/)
- [Product Documentation](https://www.ashcroft.com/learn/product-documentation)
- [Pressure Gauge Selection Tool](https://www.ashcroft.com/pressure-gauge-selection-tool/)
- [Product & Quality Certifications](https://www.ashcroft.com/about/quality-certifications/)

PROCESS INDUSTRY

- [Overview](https://www.ashcroft.com/solutions/process-industry-instrumentation/)
- [Large Projects/EPC](https://www.ashcroft.com/solutions/process-industry-instrumentation/engineering-procurement-construction-large-projects/)
- [Critical Application Solutions Experts (CASE)](https://www.ashcroft.com/solutions/process-industry-instrumentation/critical-application-solution-experts/)
- [Distributor Locator](https://www.ashcroft.com/ashcroft-distributors/)

INDUSTRIAL/OEM

- [Overview](https://www.ashcroft.com/solutions/industrial-oem/)
- [Custom Engineered Solutions (CES)](https://www.ashcroft.com/solutions/industrial-oem-custom-engineered-solutions/)

COMPANY

- [About](https://www.ashcroft.com/about/)
- [Corporate Responsibility](https://www.ashcroft.com/about/corporate-responsibility/)
- [Code of Conduct](https://www.ashcroft.com/about/corporate-responsibility/code-of-conduct/)
- [Trade Compliance](https://www.ashcroft.com/about/corporate-responsibility/trade-compliance/)
- [Product Stewardship](https://www.ashcroft.com/about/corporate-responsibility/product-stewardship/)
- [Company News & Events](https://www.ashcroft.com/news-events/)
- [Careers](https://www.ashcroft.com/careers/)
- [Contact](https://www.ashcroft.com/contact/)

 © 2026 Ashcroft Inc.. All Rights Reserved.

[Privacy Statement](https://www.ashcroft.com/privacy-policy/) | [Legal Disclaimer](https://www.ashcroft.com/disclaimer) | [Supplier Terms of Purchase](https://www.ashcroft.com/wp-content/uploads/2026/07/ashcroft-purchase-order-terms-conditions-revh-july26.pdf) | [Terms of Sales](https://www.ashcroft.com/wp-content/uploads/2023/08/terms-of-sale-ashcroft.pdf) | [Privacy Policy](https://www.ashcroft.com)

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://blog.ashcroft.com/#website",
  "@type" : "WebSite",
  "inLanguage" : "en-US",
  "name" : "Ashcroft Inc.",
  "potentialAction" : {
    "@type" : "SearchAction",
    "query-input" : "required name=search_term_string",
    "target" : "https://blog.ashcroft.com/search?term={search_term_string}"
  },
  "publisher" : {
    "@id" : "https://blog.ashcroft.com/#organization"
  },
  "url" : "https://blog.ashcroft.com"
}
```

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://blog.ashcroft.com/#organization",
  "@type" : "Organization",
  "address" : {
    "@type" : "PostalAddress",
    "addressCountry" : "US",
    "addressLocality" : "Stratford",
    "addressRegion" : "CT",
    "postalCode" : "06614",
    "streetAddress" : "250 East Main Street"
  },
  "image" : {
    "@id" : "https://blog.ashcroft.com/#logo"
  },
  "logo" : {
    "@id" : "https://blog.ashcroft.com/#logo",
    "@type" : "ImageObject",
    "caption" : "Ashcroft Logo",
    "contentUrl" : "https://4021582.fs1.hubspotusercontent-na1.net/hubfs/4021582/social-suggested-images/sales.ashcroft.comhs-fshubfsashcroft-logo-lg-2.png",
    "height" : 45,
    "inLanguage" : "en-US",
    "url" : "https://4021582.fs1.hubspotusercontent-na1.net/hubfs/4021582/social-suggested-images/sales.ashcroft.comhs-fshubfsashcroft-logo-lg-2.png",
    "width" : 200
  },
  "name" : "Ashcroft Inc.",
  "sameAs" : [ "https://www.facebook.com/AshcroftInc", "https://www.instagram.com/ashcroftinc/", "https://www.linkedin.com/company/ashcroft-inc-/", "https://www.youtube.com/user/AshcroftInc" ],
  "telephone" : "+18003288258",
  "url" : "https://blog.ashcroft.com"
}
```

```json
{
  "@context" : "https://schema.org",
  "@type" : "BlogPosting",
  "author" : {
    "@type" : "Person",
    "name" : "Marco Santoro - Business Development Leader - Europe, Temperature & Pressure",
    "url" : "https://blog.ashcroft.com/author/marco-santoro-business-development-leader-temperature-solutions-europe"
  },
  "dateCreated" : "2025-08-05T14:23:36",
  "datePublished" : "2025-08-11T11:00:00-0400",
  "description" : "Learn how to select the right RTD sensing element for your application, focusing on accuracy, construction, wiring and compliance with industry standards.",
  "headline" : "How to Select the Right RTD Sensing Element for Your Application",
  "image" : [ "https://4021582.fs1.hubspotusercontent-na1.net/hubfs/4021582/RTD_Element_Ohm_BLOG_V1.jpg" ],
  "inLanguage" : "en",
  "keywords" : [ "RTD", "temperature sensor", "pharmaceutical and biotechnology", "temperature measurement", "HVAC" ],
  "learningResourceType" : "article",
  "name" : "How to Select the Right RTD Sensing Element for Your Application",
  "publisher" : {
    "@type" : "Organization",
    "logo" : {
      "@type" : "ImageObject",
      "url" : "https://4021582.fs1.hubspotusercontent-na1.net/hubfs/4021582/social-suggested-images/sales.ashcroft.comhs-fshubfsashcroft-logo-lg-2.png"
    },
    "name" : "Ashcroft Inc."
  },
  "timeRequired" : "PT4M",
  "url" : "https://blog.ashcroft.com/how-to-select-the-right-rtd-sensing-element-for-your-application"
}
```