temperature measurement:digital temperature calibration thermometers, thermometry bridges and Automated Temperature Calibration software

If you are looking to replace an existing thermometer or thermometry bridge, or looking to set up a new in house temperature calibration laboratory to bring your organisation up to ISO 9000 standards, or maybe to bring this functional requirement back in-house, we can offer you our advice and guidance on the most appropriate precision thermometer or resistance thermometry bridge to achieve this based on our understanding of your uncertainty budget.

We offer a wide range of temperature probes with various lengths and diameters to chose from to complete the reference thermometer system.

If you require a temperature calibration heat source, we have a range of metal block temperature calibration baths for you to choose from, spaning different temperature ranges from -40C up to 1200C, enabling you to calibrate subordinate themometers against your reference thermometer. Full details on these block baths can be found on the Temperature Calibration Block Baths page.

Please request a copy of the product data sheet, either by phoning 01767 692692, email or use the Contact us link, filling in the details as required.

If you also like the idea of automated temperature calibration then the Caliso Temps software will enable you to achieve it.

You may find Guidelines for obtaining the best performance from RTDs, Prt's and Pt100’s in particular, a Sensing Devices (SDL) Ltd publication, to be of interest.

Precision Temperature Calibration Thermometers, Resistance Thermometry Bridges
ASL F900 Super Primary Standards Thermometry Bridge The Model F900 is designed specifically for resistance thermometry to provide you with the best possible accuracy. Accuracy: 20ppb (+/- 5 micro K)
ASL F18 Primary Standards Thermometry Bridge The F18 includes a wide range of features specifically tailored for temperature metrology. Accuracy: 0.1ppm (+/- 25 micro K)
ASL F600  Secondary Standards AC & DC Thermometer Bridge Accuracy: up to ±0.5mK Resolution: 0.1mK DC version for thermisor measurement.
ASL F700 Secondary Standards Thermometer Bridge Accuracy: +/-5 micro K over full range Resolution:0.25 micro K over the full range
Platinum Resistance Thermometers (Prt's) ASL provides a full range Platinum Resistance Thermometers (PRTs) for use in every application from standards calibration to site temperature measurement.
Precision Reference Resistors ASL provides a range of Standards Resistors for use when calibrating Platinum Resistance Thermometers.
Dostmann DDM 1000 Precision Thermometer Accuracy:0.1mK Resolution:0.02mK
Dostmann DDM900 Precision Thermometer Accuracy: ±0,005°C Resolution: 0,001C
Dostmann T4200 Precision Thermometer Accuracy: +/- 10mK Resolution: 0.001°C
ASL F200 Precision thermometer Accuracy:0.01C Resolution:0.001C
ASL F100 Thermometer Accuracy:0.02C Resolution:0.001C
ASL F100 Thermometer Deals: Two deals are available, call us for full details.
Dostmann T905 Bench Top Instrument The T905 Bench Top Instrument for Pt100, thermocouple types J, K, L, N, R, S, T. Measuring Range: -200°C to + 1760°C Accuracy: +/- 0.1°C Resolution: 0.1°C RS232 Digital output 0-1VDC Analogue output Integrated sensor calibration.
Dostmann T955 Bench Top Instrument The T955 Bench Top Instrument for Pt100 & thermocouple types J, K, N, L, R, S, T, Humidity & Airflow. Measuring Range : -200°C to +1760°C 0-100% RH 0-40m/s Accuracy +/-0.03°C +/-1.5& RH +/-0.5m/s
Dostmann P795 Precision Thermometer/Logger with "tare" function. 2 Channels for Pt100 probes. Accuracy:0.015C (-50C ..+199.99C) otherwise 0.025% Resolution: 0.001C. (0.01C above +199.99C) Memory with realtime clock...appr. 6000 measurements. "Smart probes" available- calibration data stored in eeprom.
Caliso "Temps" Automated Temperature Calibration Software "It does what it says on the tin" Caliso Temps is made up of 2 separate programs: Laboratory Interface where you connect your instruments and carry-out your calibration. A wide range of manufacturers hardware are supported, including web- cam support for equipment such as LIG thermometers or digital indicators which have no digital interface. Builder where you analyse your data, perform calculations, and also design and make calibration certificates.

Making precise temperature measurement or validating temperature products has never been easier with the precision thermometry systems we supply.

20 Years exprience in supplying temperature measurement & calibration products to industry & UK National Laboratories.

          Please request a copy of the product data sheet, either by phoning 01767 692692, email or use the Contact us link, filling in the details as    

          required.

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In choosing the correct hand held digital thermometer it is important to consider the uncertainties that can be permissible (uncertainty budget) for the measurement process.

If we are to use a digital thermometer for calibration of other subordinate thermometers, then the system accuracy of the reference thermometer, over the working temperature range of the device under test or calibration, will need to be at least 3 to 4 times better.

In general the accepted method of calibrating thermometers is to immerse both the reference thermometer system ( probe) and the thermometer under test (probe), in either  a metal block temperature calibration bath (sometimes referred to as a  drywell block calibrator), or in a stirred liquid calibration bath, known as calibration by comparison. Both types of bath have their own merits (and associated costs).

For primary  temperature calibration (national standards maintained at NPL) and secondary standards laboratories (UKAS accredited), temperature calibration of individual thermometers is carries out by immersing a high purity platinum precision resistance thermometer or high purity working standard thermometer into fixed point cells, which have extremely precise known temperature values: tripple point of water at 0,010000C, melt point of gallium, freezing point of indium, tin, zinc aluminium, silver, gold and copper at 1084.620C. Sub zero values are derived from the mercury tripple point at -38.83440C to the hydrogen tripple point at -259.3467C. Silver point being the highest value for realising temperature using a Platinum Resistance Thermometer in the ITS 90

Temperature Scale.

Usually the resistance thermometer is connected to a direct temperature read out bridge such as the ASL F600 or Dostmann DDM100 etc. or to a resistance thermometry bridge where the resistance of the thermometer is measured and then balanced against either an internal or an external high precision four wire resistor, which the bridge then indicates a resistance ratio value to several decimal places. This value can them be converted back into temperature by look up tables of resistance to temperature.

For industrial applications, temperature calibration will normally be carried out either at an in house facility with trained personnel skilled in temperature measurement and calibration and probably UKAS accredited, or off site at a UKAS laboratory, or at least a laboratory with a reference thermometer traceable to a UKAS lab.

It is important when choosing a temperature calibration lab that has just a UKAS "traceable certification" that they are accredited for temperature calibration using either a liquid or metal block bath, and not just for electrical simulation, as the thermometer “system” needs calibration, not just the indicator.