Ideal for Industrial Applications, high stability, low drift reference PRTs

Models Covering -200°C to 670°C

• Ideal for Industrial Applications
• Can be supplied with UKAS
• Choice of temperature ranges and sizes

In most industrial laboratories the costly and mechanically fragile SPRT is unnecessary. For these applications the uncertainties may be larger, and hence the Isotech range of semi-standards may be a more practical choice.

Usually made in stainless steel sheaths 6mm in diameter, with an Ro value of 100Ohms and an (R100 -R0 )/R0 of 0.385. A number of configurations are available since particular characteristics might be required such as short sensing length, fast response, or applicability to a particular temperature range. In this collection of semi-standards Isotech has examined not only the uses that customers put them to but also the equipment that is used to calibrate them.

Most units are now a little longer and have a slightly wider temperature range than our previous products. The stability of the semi-standard will depend upon its range of usage; your semi-standard should remain with those uncertainties between successive annual calibrations, unless you drop it or otherwise mechanically shock it.

Our semi-standards are now fitted with a handle and strain relief bush for the cable, except where otherwise stated. All are made with our own high quality 100 ohm detectors and completely assembled and calibrated in-house in our UKAS accredited and supervised Laboratory. Calibration is available with fixed points for the best uncertainties and to give the highest confidence possible.

Please note that stem conduction accounts for the biggest sources of errors during calibration. Remember that for a given immersion depth stem conduction is dependent on the temperature difference between the sensing element and ambient temperature, and on the total conductance of the thermometer assembly. It is sometimes thought (mistakenly) that a shorter thermometer will be subject to less stem conduction.