# ITS90 CVD RTD Calculator — Harwell RTD Calculator > RTD temperature and resistance calculation tool using ITS-90 and CVD methods. (iPhone/iPad app by HARWELL LLC.) - Source: https://appshunter.io/ios/app/its90-cvd-rtd-calculator/id1552330847 (this page in markdown: same URL + `.md`) - Developer: [HARWELL LLC](https://appshunter.io/developer/1552330849) - Category: Utilities, Reference - Price: Free - Rating: 3.00/5 from 1 App Store ratings · 1 written reviews indexed - Age rating: 4+ - Requires: iOS 14.1 · 1 MB - Languages: English - Released: 2021-03-05 - Data updated: 2026-10-25 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/its90-cvd-rtd-calculator/id1552330847/reviews.md ## What is ITS90 CVD RTD Calculator? A handy app for calculating resistance to temperature and temperature to resistance with Platinum RTDs (Resistance Temperature Detector). Choose from either ITS-90 (International Temperature Scale of 1990) or CVD / (Callendar–Van Dusen) calculation. Use the default coefficients or use your own if you have a calibrated device. ITS-90 requires your RTD probe resistance at the Triple Point of Water and calibration coefficients. ITS-90 temperature input is limited to -189°C to 660°C. CVD calculation allows you to use standard or custom ice point / 0°C resistance values and either standard or custom coefficients. CVD temperature input is limited to -200°C to 850°C Supports a multitude of sensors including IEC 751, Industrial, Standard, Reference, and Secondary Reference probes/sensors. ## Key features - ITS-90 and CVD calculations - Resistance to temperature conversion - Temperature to resistance conversion - Customizable coefficients - Support for multiple RTD sensor types - Specific temperature range limits ## Is ITS90 CVD RTD Calculator safe? Not enough ratings yet to assess ITS90 CVD RTD Calculator. ## Is ITS90 CVD RTD Calculator legit? ITS90 CVD RTD Calculator appears to be a legitimate app. The AppsHunter Legitimacy Score for ITS90 CVD RTD Calculator is 83 out of 100 points across 7 verification signals from App Store and developer data. ## Recent user reviews (1 of 1) All indexed reviews: https://appshunter.io/ios/app/its90-cvd-rtd-calculator/id1552330847/reviews.md ### 3/5 — Some problems *2021-03-22* This is a great idea for and app and easy to use. The problem is that the temperature calculation below 0 Deg C do not seem to be accuracy. Above 0 C they work great. **Developer response:** Hello Brett, we apologize for calculation error. We found the bug in the formula and fixed it. We would love to get in touch about your experience and use. Kindly contact us at info@harwellusa.com Thanks! ## Frequently asked questions about ITS90 CVD RTD Calculator ### What is ITS90 CVD RTD Calculator used for? ITS90 CVD RTD Calculator is used to convert between resistance and temperature for Platinum RTD sensors. It supports both the ITS-90 and Callendar–Van Dusen (CVD) calculation methods. ### What are the temperature limits for ITS90 CVD RTD Calculator? For ITS-90 calculations, the temperature input is limited to -189°C to 660°C. For CVD calculations, the temperature input is limited to -200°C to 850°C. ### Can I use my own calibration coefficients with ITS90 CVD RTD Calculator? Yes, you can use your own calibrated device coefficients. The app allows you to input custom coefficients for both ITS-90 and CVD calculations if you have a calibrated device. ### What types of RTD sensors does ITS90 CVD RTD Calculator support? The app supports a multitude of sensors including IEC 751, Industrial, Standard, Reference, and Secondary Reference probes/sensors. ### How accurate is ITS90 CVD RTD Calculator? The accuracy of the calculations depends on the quality of the input data and coefficients. The app provides the tools for precise conversion based on standard or custom parameters. ### Is ITS90 CVD RTD Calculator available on multiple platforms? Based on the provided data, the app is available for mobile devices. Specific platform availability (e.g., iOS, Android) is not detailed but it is a mobile application. ### When was ITS90 CVD RTD Calculator last updated? The latest version of ITS90 CVD RTD Calculator was updated on November 15, 2021. ### What is the user rating for ITS90 CVD RTD Calculator? ITS90 CVD RTD Calculator has a rating of 3.0 stars from 1 rating. ## Version history (last 5 releases) ### 2.2 — 2021-11-15 - Fixed loading screen/added back button ### 2.1 — 2021-11-04 - Fixed bugs ### 2.0 — 2021-11-03 - Fixed bugs ### 1.9 — 2021-11-02 - Fixed bugs ### 1.8 — 2021-11-01 - Added Report bug/Support function - Changed IEC 60751 to RTD with Thermometer type ## Apps similar to ITS90 CVD RTD Calculator | App | Rating | Price | Category | | --- | --- | --- | --- | | [mDNS Utility](https://appshunter.io/ios/app/mdns-utility/id918208340) | 1.6 (5) | $0.99 | Utilities | | [i Sound Level Meter](https://appshunter.io/ios/app/i-sound-level-meter/id912170360) | 4.4 (38) | Free | Utilities | | [Psychology Book - with Facts](https://appshunter.io/ios/app/psychology-book-with-facts/id1489042300) | 4.7 (1,153) | Free | Utilities | | [魔方寻亲](https://appshunter.io/ios/app/id1535752900) | — | Free | Utilities | --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-25.*