Title: Determination of thermometer characteristics : Guideline DKD-R 5-6, Revision 1
Authors: Members of the DKD Technical Committee Temperature and Humidity, 2003 to 2008., Physikalisch-Technische Bundesanstalt (PTB), ISNI: 0000 0001 2186 1887
Contributors: HostingInstitution: Physikalisch-Technische Bundesanstalt (PTB), ISNI: 0000 0001 2186 1887
Resource Type: Text / Technical Requirement
Publisher: Physikalisch-Technische Bundesanstalt (PTB)
Rights: https://creativecommons.org/licenses/by-nc-nd/3.0/de/
CC by-nc-nd 3.0
Relationships: IsVariantFormOf: DOI 550.20180828AG
Dates: Available: 2020-06-10
Created: 2018-09
Updated: 2020-06
File: Download File (application/pdf) 954.39 kB (977292 Bytes)
MD5 Checksum: 1a2de858a69ed7f18f73b0cc98195b1c
SHA256 Checksum: 152ad88d0e772d6d4dde6986ce0c38df977328c267fe8f24da30121b60502f1e
Keywords: DKD ; guideline ; thermometer characteristics ; temperature ; ITS-90
Abstract: The purpose of this guideline is to define generally valid procedures for the approximation of the characteristic curves of industrially used thermometers in order to create a uniform and industry-wide basis for the surveillance of test equipment. Likewise, the user of this guideline – i.e. the calibration laboratory as well as the user of the thermometer – shall be given
instructions regarding the handling of approximation equations as well as the performance of the actual approximation.

Basically, this guideline is valid for all thermometers. However, it is especially tailored to the requirements of platinum resistance thermometers (especially Pt-100), thermocouples and thermistors. As these instruments have very different measurement uncertainties, depending on the type of sensor and temperature range, this guideline has been designed for different requirements related to the measurement uncertainty. For some thermometer types (e.g. thermometers with electronic display or liquid-in-glass thermometers) the determination of a characteristic curve involves fundamental problems. The present guideline is not applicable for these types of thermometer.

This guideline is not intended to develop or prescribe newer or better approximation methods or characteristic curve types than those currently in use.
It rather seeks to recommend the optimum type(s) of characteristic for certain boundary conditions – such as temperature range and required measurement uncertainty – which are state of the art today. These recommendations are compatible with existing software and measuring instruments and can be easily entered or integrated. Possibly, there are other types of characteristics which are equally suited or may even be better than those described here. However, in the case of limited dissemination or
practicability, other mathematical descriptions of characteristic curves should only be used in justified cases.
Citation: Guideline DKD-R 5-6, Determination of thermometer characteristics, Edition 09/2018, Revision 1, Physikalisch-Technische Bundesanstalt, Braunschweig and Berlin. DOI: 10.7795/550.20180828AGEN