Today, the total range of vacuum pressure accessible to measurement extends from atmospheric pressure (about 1000 mbar (750 Torr)) down to 10-12 mbar/ 0.75•10-12 Torr, i.e. it extends over 15 powers of ten. The instruments used for measuring the pressure within this wide range are called vacuum gauges. For physical reasons it is not possible to create a single vacuum sensor through which it might be possible to perform quantitative measurements within the entire pressure range. Therefore, a variety of different vacuum gauges are available, each with their own characteristic measurement range which commonly extends over several powers of ten.
At common so-called mechanical vacuum gauges (BOURDONVAC, DIAVAC, capsule vacuum gauges) the pressure is determined directly by recording the force acting on the surface of a diaphragm. In this case of direct (or absolute) pressure measurements, the readings obtained through the vacuum gauge are independent of the type of gas and the pressure which is to be measured. The pressure range is approx. from 1000 mbar (atmospheric pressure, 750 Torr) to 1 mbar (0,75 Torr).
Common so-called mechanical vacuum gauges (BOURDONVAC, DIAVAC, capsule vacuum gauges) determine pressure directly by recording the force acting on the surface of a diaphragm. In this case of direct (or absolute) pressure measurements, the readings obtained through the vacuum gauge are independent of the type of gas and the pressure which is to be measured. The pressure range is approx. from 1000 mbar (atmospheric pressure, 750 Torr) to 1 mbar (0,75 Torr).
The active sensors (CERAVAC, THERMOVAC, PENNINGVAC and IONIVAC) are made for direct integration into the vacuum system control. Display and operation units are optional. The passive sensor (PIEZOVAC) is delivered completely including display and operation unit.
Additionally to the transmitters listed so far there are some more passive sensors available.
The connection cables for the sensors and transmitters are specific to the sensors and operating units. The cable length varies between 5 m and 100 m..
Frequently additional display and operating instruments are needed for the purpose of integration within system controllers to provide the transmitters with the necessary supply voltage or to locally display the measured values. For such applications Oerlikon Leybold Vacuum offers different instruments. The DISPLAY line and CENTER line are designed each for a specific range of applications.
The operating units of the COMBIVAC Series for Pirani and Penning passive sensors perform well in radiation resistant and bakeable vacuum systems. The use of these operating units reduces costs of ownership due to the increase in senor lifetime and proven overall reliability of passive sensors.
The three-channel display and operating unit IONIVAC IM 540 offers, by combination of up to 4 different principles of measurement – Pirani, capacitive, Bayard-Alpert and Extractor–, complete coverage and control of the vacuum pressure in the range between 10-12 mbar and atmospheric pressure.
VACVISION offers a platform capable of configuring vacuum systems. The controller automatically detects up to 3 active vacuum gauge heads, five valves, and one each forevacuum and one high vacuum pump
In all applications where simple, fast and accurate pressure control is desired and necessary several pressure switch and control devices are available. For example the universal pressure switch PS 115, the low pressure safety switch PS 113A, the switching amplifier SV 110, the diaphragm pressure regulator MR or the electronic pressure control system C MOVE which in connection with the electronic control valve Move 1250 or Move X controls the gas flow at a individual configured pressure.