The nominal boiling point of nitrogen is –196°C at one atmosphere of pressure. The defining triple point of argon is –189.3442°C. While there is a difference between the nominal boiling point of nitrogen and the argon triple point, the difference can be corrected for mathematically, and an uncertainty of less than 2 mK from the actual argon triple point is achievable.
Fluke Calibration’s LN2 Comparison Calibrators consist of a vacuum-sealed stainless steel Dewar Flask, a high-purity copper block, and a precision-fit lid. The dewar is filled with LN2 and the copper block is suspended in it; an SPRT is inserted into the block and a calibration is performed against your own calibrated SPRT. The 7196B-4 includes four 8-mm (0.32″) wells. The 7196B-13 includes five 8-mm (0.32″) wells and eight 6.35-mm (0.25″) wells.
Fluke Calibration’s LN2 Comparison Calibrators are neither expensive nor complicated to use. If you need supporting data or would like to discuss the theory of operation of an LN2 Comparison Calibrator, call Fluke Calibration today. (Or come to one of our calibration training courses and we’ll show you.)
