If you need to do calibrations at the triple point of argon but don’t want the complexity and cost of using an argon triple point cell, Hart’s Model 7196 LN2 Comparison Calibrators will solve your problems. And they do it for less than half the price of other argon triple point simulators.
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.
Hart’s LN2 Comparison Calibrators consist of a super-insulated glass dewar, 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 7196-4 includes four 8-mm (0.32") wells. The 7196-13 includes five 8-mm (0.32") wells and eight 6.35-mm (0.25") wells.
Hart’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 Hart Scientific today. (Or come to one of our training courses and we’ll show you.)
Nominal –196°C depending on atmospheric pressure
7196-4: four 8 mm (0.32”) I.D. wells
7196-13: five 8 mm (0.32”) I.D. wells, eight 6.35 mm (0.25”) I.D. wells
Both blocks: 275 mm immersion from top of lid to bottom of well, 150 mm immersion into copper block
180 mm O.D. x 385 mm high
Typically better than 2 mK
3.5 liters of liquid nitrogen
LN2 Comparison Calibrator, 4 holes
LN2 Comparison Calibrator, 13 holes