Semi Standard PRTs
800x-_Page 51 – Semi Standard

Semi Standard PRTs


Product Description

Semi Standard PRTs

These industrial platinum resistance thermometers are ideal for field and lab use. Suitable for use as working standards in Dry Blocks and Liquid Baths or as high accuracy probes for our range of True Temperature Indicators.

All the thermometers are metal sheathed and both less fragile, and more affordable than the Isotech range of true Standard Platinum Resistance Thermometers that are used in laboratories and our found in our publication “Solutions for Primary and Secondary Laboratories”.

All the thermometers use handmade coil wound platinum sensing elements to give high accuracy and low drift. Isotech’s UKAS accredited lab can calibrate to the smallest of uncertainties.

Calibration should be specified to suit the particular operating range and application. Isotech can advise on which service is appropriate to match the temperature range and application.

Isotech have generated a long history of many of our semi-standards. Here are a few documented facts: The 935-14-95 model has the widest temperature range and in consequence is likely to suffer the largest changes in characteristics. Guy Snelling sent the following email about the 935-14-95.

Working Industrial Standards These thermometers use premium grade wire wound elements to IEC-751 and the same internal construction as our working Standard SPRTs. The 95L is optimised for low temperature with minimum stem conduction. The 95H is optimised for high temperature operation. Both models employ strain free construction.

Technical Feature Value
Ro 100Ω ± 0.05Ω
Alpha 0.003850 ± 0.000005
Standard IEC 60751
Stability 0.010Ω/ year
Recommended Current 1mA
Self Heating at 1mA 0.004°C
Calibration Optional UKAS Calibration at extra cost. See table for typical uncertainties.
Connection 4 Wire
Max. Handle Temperature 80°C