Measuring pressure from atmospheric pressure to high vacuum range by one principle is impossible in today's technology.
Hence, complex vacuum gauges which have the sensor head with different measurement principles are prevailed. But there are some demerit on the complex vacuum gauges as below;
1. All sensor heads need to be replaced when a sensor head is broken.
2. Easy to break for the complexity of sensor heads
3. Sensor head is expensive
ULVAC adopts the separate sensor head method (patent pending) with its sensor head selectable at customer's choise. It's capable of measuring wide range of pressure, lowering runninng cost and stress on emviroment.
This series is hot cathode type ionization vacuum gauge, capable of measuring pressure in the 9.9 to 5 x 10-8 Pa (7.4 x 10-2 to 3.75 x10-10 Torr, 9.9 x 10-2 to 5 x 10-10 mbar)(Metal gauge, GI-M2), 6.7 x 10-1 to 10-6 Pa (5 x 10-3 to 9.75 x10-9 Torr, 6.7 x 10-3 to 1.3 x 10-8 mbar)(Glass gauge, GI-D7) range using triode tube or B-A type sensor heads.