";s:4:"text";s:3525:" RTD assemblies made from iron or copper are also used in some applications. Sheaths and tubes improve fragility but increase response time Standard Platinum Resistance Thermometer Calibrations from the Ar TP to the Ag FP G. F. Strouse Chemical Science and Technology Laboratory Process Measurements Division Thermometry Group January 2008 U.S. Department of Commerce Carlos M. Gutierrez, Secretary National Institute of Standards and Technology James M. Turner, Deputy Director Sheaths and tubes improve fragility but increase response time R and S types that use platinum are more expensive Suitable for use as working standards in Dry Blocks and Liquid Baths or as high accuracy probes for our range of True Temperature Indicators. So for example, if we are going to measure between 0 and 100 °C (32 and 212 °F), RTD resistance will range from 100 Ω to 138.5 Ω. The resistance elements are rated in accordance with BS EN 60751:2008 as: We would choose R1 = 120 Ω.
This is why laboratory standard thermometers replace the metal sheath with a glass construction.
RTDs in industrial applications are rarely used above 660 °C. Our SPRTs have all the features you would expect in a world-class design -- gold-plated spade lugs, a strain-relieved four-wire cable, convection prevention disks, the finest quartz glass available, delustered stems, and the purest platinum wire available.
These elements nearly always require insulated leads attached.
Choosing the right standard platinum resistance thermometer (SPRT) as your primary standard may be the most critical purchase decision in your lab. How Platinum Resistance Thermometer Works?
For a balanced bridge usual setting is with R2 = R1, and R3 around the middle of the range of the RTD.
This standard platinum resistance thermometer is used as the temperature standard in some of the top national laboratories from all over the world. The simplest resistance-thermometer configuration uses two wires.
Gauge temperatures accurately with the 670 SPRT from Isotech! RTDs, which have higher accuracy and repeatability, are slowly replacing Common RTD sensing elements constructed of platinum, copper or nickel have a repeatable resistance versus temperature relationship (The significant characteristic of metals used as resistive elements is the linear approximation of the resistance versus temperature relationship between 0 and 100 °C.