THERMAL CONDUCTIVITY VACUUM GAUGE Russian patent published in 1998 - IPC

FIELD: vacuum gauges, measurement of pressure of rarefied gases. SUBSTANCE: proposed thermal conductivity vacuum gauge has primary converter 1 including two temperature-sensitive resistors, first one 3 sensitive to pressure of rarefied gas and second one 2 being temperature sensor connected with first leads to common wire and with second leads to first leads of first and second fixed resistors 6, 5, to first leads of first and second electron keys 9, 8 correspondingly, second leads of electron keys are connected to first leads of third and fourth fixed resistors 7, 4 correspondingly. First temperature-sensitive resistor 3 is connected with its second lead to inverting input of first operational amplifier which noninverting input is coupled to second lead of second temperature-sensitive resistor 2. Its output is connected to second leads of first, second, third and fourth fixed resistors and to inputs of first 11 and second 12 storage and retrieval devices which are coupled through fifth and sixth fixed resistors 13, 14 to inverting and noninverting inputs of second operational amplifier 17 which noninverting input is connected through seventh fixed resistor 15 to common wire and which output is connected through eighth fixed resistor 16 to inverting input. Controlling inputs of first and second keys 9, 8 and first storage and retrieval device 11 are coupled to first output of controlling generator 17 which second output is linked to controlling input of second storage and retrieval device 12. Output of second operational amplifier 17 is out[output of vacuum meter. EFFECT: expanded range of working temperatures. 1 dwg