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.
