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 100Ω 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.
