The inner part of the BOURDONVAC is a Bourdon tube, which is bent into a circular arc and is connected to the vacuum system.
Due to the effect of the external atmospheric pressure, the end of the tube bends more or less during the evacuation process. This actuates the pointer arrangement which is attached to this point. The corresponding pressure can be read off on a linear scale.
With BOURDONVAC gauges it is possible to roughly determine pressures from atmosphere to 1mbar/torr.
As the mechanism is exposed to local atmospheric pressure, it can be affected by fluctuations in atmospheric pressure.
Those gauges are designed for rough pressure measurement in harsh environments:
CAPSULE gauges operate with a diaphragm connected to a dial.
They contain a hermetically sealed, evacuated and thin-walled diaphragm capsule located within the instrument. As the vacuum pressure reduces the capsule bulges. This movement is transferred via a system of levers to a pointer and the pressure can be read off on a linear scale.
As the measuring cell is hermetically sealed against the outside environment, it is not affected by changes in atmospheric pressure, making it more reliable at pressures below 10 mbar/torr.
As CAPSULE gauges are better to read lower pressures, we offer it with two full scales:
It also comes with either:
Where the BOURDONVAC is great with corrosive media, but affected by atmospheric pressure, and the capsule gauge is less capable with corrosive media, but not affected by ambient pressure, the DIAVAC DV 1000 combines the best features of both into a single gauge.
Inside the case is a diaphragm capable of absolute pressure measurements, and a sealed and evacuated vacuum chamber is separated by a diaphragm from the vacuum pressure to be measured. This serves as the reference quantity.
With increasing evacuation, the difference between the pressure which is to be measured and the pressure within the reference chamber becomes less, causing the diaphragm to flex. This flexure may be transferred by mechanical means like a lever, for example, to a pointer scale.
The DIAVAC DV 1000 is made for rough pressure measurement in corrosive environments as the sensitive parts are in a sealed reference volume and the materials exposed to vacuum in the sensing cell are Stainless steel/FPM.
To increase the accuracy of the gauge: each scale is individually calibrated for optimum performance.