Contact pressure gauges by WIKA
Wherever the process pressure has to be indicated locally and, at the same time, circuits need to be switched, contact pressure gauges find their application. The switch contacts (also called alarm contacts) make or break circuits dependent upon the pointer position of the indicating measuring instrument.
In the wide WIKA portfolio, you will find the right contact pressure gauge for each type of pressure:
The switch contacts or alarm contacts in contact pressure gauges make or break the circuit depending on the pointer position. If the reading is significantly above or below a set value, they trigger an alarm (hence also the term alarm contact). They are also suitable for starting, stopping or switching processes.
Magnetic snap-action, inductive and electronic contacts of a contact pressure gauge are usually mounted behind the dial and can be set to any point across the entire scale range via the set pointer. The instrument pointer (actual value pointer) of the contact pressure gauge moves freely. Depending on the instrument version, the switch contacts are factory-set or can be adjusted using an adjustment key in the window.
Depending on the switch contact, contact pressure gauges are distinguished as follows:
Contact gauges with magnetic snap-action contact
Contact gauges with magnetic snap-action contact can be installed under a whole range of operating conditions. The snap-action characteristic of the contact system is achieved by an adjustable permanent magnet at the set pointer. Thus the contacts are largely protected against arcing effects. The signal output is achieved ahead of the movement of the pointer. If contact gauges with magnetic snap-action contact are used properly, they will function without any problems for many years.
Contact gauges with inductive contact
Contact gauges with inductive contact are mainly used in two fields of application:
- in hazardous areas, zones 1 and 2
- at high switching frequency
Inductive contacts work without any kind of mechanical contact, consequently they are wear-resistant, and there's absolutely no influence on the mechanics of the contact gauge. Inductive contacts can be used universally, even with filled contact gauges, and are insensitive to aggressive ambience.
Contact gauges with electronic contact
Contact gauges with electronic contact can switch small loads, e.g. those usual in programmable logic controllers (PLC), directly. The usual advantages of an inductive contact, such as fail-safe contact operation, no wear due to the proximity contact operation and virtually no effect on the indication of the measuring system, also apply here.
Contact gauges with reed contact
Due to their design and low weight, reed contacts are particularly vibration resistant. Contact gauges with reed contacts can switch loads up to 230 V/1 A directly, as well as giving a secure contact with extremely low currents. They are also suitable as direct inputs to PLCs.
Which standard regulates contact gauges?
Sliding and magnetic snap-action contacts fitted in pressure gauges and thermometers with housing diameters of 100 and 160 mm are governed by DIN 16085.
