Selecting a Contact Pressure Gauge Correctly: Match Switching Contact, Switching Capacity and Hysteresis to the Application

→ Product category: Contact Pressure Gauge

 

A pressure gauge on a machine should not only display the current pressure.

At:

6 bar

a signal should also be sent to the control system.

When the pressure drops sufficiently again, the signal should be reset.

At first glance, all that appears to be required is a:

pressure gauge with electrical contact

.

In practice, however, this specification is not sufficient.

For reliable operation, the following must be defined, among other things:

• measuring range and process connection,
• measuring medium and materials,
• number of switching points,
• switching direction,
• contact type,
• switching voltage and switching current,
• type of connected load,
• required switching hysteresis,
• pressure pulsations and vibrations,
• PLC connection,
• Ex requirements where applicable.

One particularly important point is the electrical load on the contact.

A contact pressure gauge is not a power switch. The integrated limit signal contact may only be operated within its permissible electrical load limits.

For larger loads, the consumer is therefore often not switched directly. Instead, a configuration such as:

contact pressure gauge → interface relay → load

or:

contact pressure gauge → PLC input → control logic

is used.

Switching hysteresis is equally important.

If a contact switched on and off again at exactly the same pressure, even small pressure fluctuations could cause continuous switching.

The result would be:

ON → OFF → ON → OFF

within a short period of time.

Correct selection of a contact pressure gauge therefore always requires the mechanical pressure measurement and the electrical switching function to be considered as one complete system.

Contact pressure gauges can be found at ICS Schneider under Contact Pressure Gauges. Further solutions can be found under Pressure Measurement Technology.

What is a contact pressure gauge?

A conventional mechanical pressure gauge displays the current process pressure locally.

A contact pressure gauge combines this indication with one or more electrical limit signal contacts.

The device therefore performs two functions:

display pressure + monitor electrical switching point

Operating principle

The instrument pointer displays the current pressure.

In addition, a setpoint pointer or limit value is adjusted.

When the actual-value pointer moves above or below this set value, the electrical contact is actuated.

Typical applications

• pump monitoring,
• compressors,
• hydraulic systems,
• filter monitoring,
• process plants,
• compressed-air systems,
• limit-value signalling,
• start/stop controls.

Contact pressure gauge or pressure switch?

Contact pressure gauges and pressure switches can both monitor a pressure limit.

However, they serve different requirements.

Feature	Contact pressure gauge	Pressure switch
Local pressure indication	Yes	Not available depending on version
Limit-value switching	Yes	Yes
Mechanical indication without auxiliary power	Yes	Not necessarily
Multiple visible switching points	Possible depending on version	Device-dependent
Typical strength	Combined indication and switching function	Primarily switching function

A contact pressure gauge is particularly useful when

the operator needs to:

• see the current process pressure,
• monitor a limit value

at the same time.

Select the measuring range correctly first

Before considering the electrical contact, the actual pressure gauge must first be sized correctly.

The switching point must be within a sensible measuring range

Example:

A system normally operates at:

5 … 6 bar

and should generate a warning at:

7 bar

.

A pressure gauge with an unnecessarily large measuring range would still work, but the desired switching point would be less clearly resolved on the scale.

Also consider overload

The following must additionally be taken into account:

• normal operating pressure,
• possible pressure spikes,
• start-up pressure,
• test pressure,
• permissible overload of the measuring instrument.

The contact pressure gauge should therefore not be selected solely according to the desired switching point, but according to the complete pressure profile of the system.

Define switching point and switching direction

The specification:

switching point 6 bar

alone is not yet unambiguous.

The switching direction must also be defined

For example:

contact closes when pressure rises above 6 bar

or:

contact opens when pressure rises above 6 bar

With falling pressure, the required function may be different

For example, for minimum-pressure monitoring:

pressure falls below 3 bar → alarm

The desired contact function must therefore always be defined together with the direction in which the pressure is changing.

Useful information to provide in an inquiry

• switching point,
• rising or falling pressure,
• whether the contact should open or close,
• number of required contacts.

Which contact types are available?

Depending on the device, different contact technologies are available for contact pressure gauges.

For the WIKA PGS23, for example, the following are available:

• magnetic snap-action contacts,
• reed switches,
• inductive contacts,
• electronic contacts.

The technologies have different characteristics and should be selected according to the electrical application.

Contact type	Typical strength	Typical application
Magnetic snap-action contact	Mechanical, clearly defined switching action	Simple control and signalling circuits within the permissible contact load
Reed contact	Encapsulated contact, suitable for signal applications	PLC applications, among others
Inductive contact	Non-contact detection	Process industry and corresponding hazardous-area applications
Electronic contact	Electronic signal output	PLC and automation applications

Magnetic snap-action contact

With a magnetic snap-action contact, the switching process is triggered with magnetic assistance.

Advantage

The contact does not merely switch slowly in line with pointer movement, but instead produces a clearly defined switching action.

Typical application

Magnetic snap-action contacts are suitable for conventional:

• signalling circuits,
• relay control circuits,
• limit-value monitoring

within the electrical limits specified for the particular contact.

Consider mechanical interaction

Because the contact function is mechanically coupled to the pointer mechanism, the switching characteristics of the specific contact must be taken into account.

Reed contact

A reed contact consists of magnetically actuated contact elements in an encapsulated system.

Typical advantages

• compact design,
• encapsulated contact point,
• suitable for signal applications,
• usable for corresponding PLC applications.

Electrical load limits also apply here

A reed contact must not automatically switch any arbitrary:

• solenoid valve coil,
• contactor coil,
• motor load

directly.

The permissible electrical values of the specific version must be checked.

Inductive contact

Unlike a conventional mechanical contact, an inductive contact operates without physical contact.

Advantage

There is no mechanical contact point at which an electrical arc is generated during every switching operation.

Typical application

Inductive contacts are used particularly in demanding industrial applications and – with a suitably approved version and circuitry – in hazardous areas.

Consider signal processing

An inductive contact is not necessarily wired like a simple potential-free switch.

Depending on the version, suitable evaluation electronics or an appropriate switching amplifier may be required.

Electronic contact

Electronic contacts are particularly useful when the contact pressure gauge is to be integrated directly into a modern control system.

Typical application

For example:

contact pressure gauge → PLC digital input

Advantage

No larger load has to be switched directly by the mechanical measuring instrument.

Important

Electronic contacts also have defined:

• supply voltages,
• signal levels,
• maximum output currents.

These must be compatible with the control-system input.

Size the switching capacity correctly

One of the most important questions when selecting a contact pressure gauge is:

What electrical load actually needs to be switched?

Do not specify voltage alone

The specification:

24 V DC

is not sufficient.

The following must also be known:

current consumption of the load

Example

A solenoid valve coil operates at:

24 V DC

and requires:

0.8 A

.

It must then be checked whether the specific contact is actually permitted to switch this load:

24 V DC / 0.8 A

under the applicable operating conditions.

Switching capacity may additionally be specified in terms of

• W,
• VA,
• maximum voltage,
• maximum current.

All relevant limits must be observed.

Do not treat AC and DC loads the same

The permissible switching capacity of a contact may differ for AC and DC voltage.

Why is DC often more demanding?

When a DC circuit is opened, there is no regular natural current zero crossing as there is with AC.

An arc that forms may therefore be more difficult to extinguish.

Consequence

A permissible AC switching capacity must not automatically be assumed to apply identically to DC.

For selection, always use the contact specification that corresponds to the actual voltage and type of load.

Pay particular attention to inductive loads

Relay, contactor and solenoid valve coils are inductive loads.

A counter-voltage is generated when switching off

The energy stored in the inductance attempts to maintain the current flow.

This can generate high voltage spikes at the switching contact.

Possible consequences

• contact erosion,
• arc formation,
• reduced contact service life,
• EMC interference.

Use suitable protective circuitry

Depending on whether the circuit is AC or DC, appropriate measures can be used to limit switching-off voltage peaks.

The specific circuitry must be matched to the load and control circuit.

When an interface relay is useful

A contact pressure gauge should not unnecessarily switch the actual power load itself.

Typical arrangement

contact pressure gauge → interface relay → power load

Advantages

• lower electrical load on the pressure gauge contact,
• higher switching capacity on the output side,
• galvanic or functional isolation depending on the relay,
• easier replacement,
• additional contact functions possible.

Example

The contact pressure gauge merely signals:

pressure > 8 bar

to an interface relay.

The relay then switches a:

• contactor,
• solenoid valve,
• warning device

.

Connecting a contact pressure gauge to a PLC

In modern systems, direct load switching is often not required.

Instead, the contact pressure gauge merely sends a limit-value signal to the PLC.

Signal path

process pressure → contact pressure gauge → PLC → control program → actuator

Advantage

The actual logic can be implemented in the PLC.

For example:

• switching delay,
• alarm acknowledgement,
• interlocking,
• time monitoring,
• fault indication.

Select a suitable contact type

For the WIKA PGS23, electronic contacts and reed switches, for example, can be used for PLC applications.

What does switching hysteresis mean?

Switching hysteresis describes the difference between the pressure at which a contact changes state and the pressure at which it switches back when the pressure moves in the opposite direction.

Example

The contact switches at rising pressure at:

6.0 bar

and, when pressure falls, switches back only at a lower pressure, for example.

The difference between these two points is the:

switching hysteresis

Why is hysteresis necessary?

Without sufficient difference, a process pressure such as:

5.98 → 6.02 → 5.99 → 6.01 bar

could cause continuous switching.

Do not confuse hysteresis with measurement accuracy

Switching hysteresis does not describe the accuracy class of the pressure gauge.

The following must be distinguished:

• accuracy of the pressure indication,
• repeatability of the switching point,
• switching differential or hysteresis.

Prevent contact chattering caused by pressure fluctuations

Process pressure is rarely completely constant.

Significant pressure pulsations can occur particularly with:

• piston pumps,
• compressors,
• fast-switching valves,
• hydraulic systems.

If the switching point lies directly within the pulsation range

the pointer may repeatedly cross the limit value.

This results in:

contact ON → OFF → ON → OFF

Possible countermeasures

• suitable switching hysteresis,
• damping of pressure pulsations,
• liquid-filled pressure gauge,
• electrical or PLC-side delay,
• suitable positioning of the switching point.

Using multiple switching contacts correctly

Depending on the version, a contact pressure gauge can monitor several limit values.

For the WIKA PGS23.100 and PGS23.160, for example, up to:

4 switching contacts

per device are possible.

Typical application with two contacts

For example:

Contact 1: minimum pressure 3 bar

Contact 2: maximum pressure 8 bar

This can create window monitoring

The process should operate within:

3 … 8 bar

.

A signal is generated below or above this range.

Further possibilities

• pre-warning + shutdown,
• pump ON + pump OFF,
• minimum + maximum,
• multi-stage alarm signalling.

Consider vibrations and pressure pulsations

Mechanical contact pressure gauges contain moving parts.

Strong vibrations can therefore:

• move the pointer,
• influence the switching point,
• cause contact chattering,
• reduce service life.

Distinguish between two different influences

Vibration:

The entire measuring point or machine vibrates mechanically.

Pressure pulsation:

The process pressure itself changes rapidly.

Both can occur simultaneously

For example on a piston pump.

When case filling is useful

A liquid filling in the pressure gauge case can damp the movement of the pointer.

Typical operating conditions

• machine vibrations,
• dynamic pressure loads,
• rapid pointer movements.

Advantage

The indication becomes steadier and mechanical components are subjected to less stress.

Also consider the switching function

Stronger damping simultaneously changes the dynamic response of the pointer.

For very rapid pressure changes, it must therefore be checked whether the response behavior is suitable for the application.

Consider measuring medium and materials

Even the best switching concept is unsuitable if the measuring system is not compatible with the process medium.

The following should be checked

• measuring medium,
• temperature,
• pressure range,
• viscosity,
• tendency to crystallize,
• corrosiveness,
• solids content.

Bourdon tube or diaphragm?

A Bourdon tube pressure gauge is suitable for many conventional gaseous and liquid media.

For:

• lower pressure ranges,
• high-viscosity media,
• contaminated media,
• special overload requirements

a diaphragm-type version may be advantageous.

Consider overload and pressure spikes

The desired switching point says nothing about the maximum pressure that can actually occur at the measuring point.

Example

Operating pressure:

4 bar

Switching point:

6 bar

short-term pressure spike:

12 bar

Problem

A pressure gauge selected only for the normal operating range can be mechanically overloaded by such a pressure spike.

Therefore consider

• maximum process pressure,
• pressure spikes,
• test pressure,
• overload limit of the measuring instrument.

Contact pressure gauges in hazardous areas

A contact pressure gauge with an electrical limit signal contact can form part of a circuit in a hazardous area.

Select the contact type specifically

For the WIKA PGS23, for example, inductive contacts are available for corresponding applications in hazardous areas.

Do not consider the pressure gauge alone

The explosion-protection concept also includes, among other things:

• the specific device version,
• Ex marking,
• electrical circuit,
• evaluation unit,
• wiring,
• zone classification.

Simply selecting an “inductive contact” therefore does not replace verification of the complete Ex design.

Typical faults with contact pressure gauges

Observation	Possible cause	Recommended check
Contact continuously switches on and off	Pressure pulsation or insufficient effective hysteresis	Check pressure profile, damping and switching logic
Contact wears unusually quickly	Electrical load too high	Check switching current, voltage and load type
Contact wears particularly quickly when switching a solenoid valve	Inductive switching-off voltage spikes	Check protective circuitry or interface relay
PLC does not reliably detect the contact	Unsuitable contact type or incorrect input circuitry	Compare contact and PLC specifications
Switching point does not match exactly for rising and falling pressure	Switching hysteresis	Measure switch-on and reset points separately
Pointer oscillates strongly	Pressure pulsation or vibration	Check measuring point, damping and instrument filling
Contact triggers sporadically under vibration	Mechanical vibration affects the pointer mechanism	Check installation and damping
Pressure gauge indicates correctly, but switching contact does not operate	Electrical connection or contact fault	Check contact circuit separately
Contact switches in the wrong direction	Incorrect contact function selected or wired	Check switching logic for rising/falling pressure
Switching point has poor repeatability	Vibration, friction, pressure pulsation or unsuitable contact technology	Assess measuring point and contact type
Pressure gauge is damaged by pressure spikes	Overload limit exceeded	Determine maximum pressure and pressure spikes

Systematic selection procedure for a contact pressure gauge

1. Determine the measuring medium: Consider gas, liquid, aggressive or high-viscosity media.
2. Determine process temperature: Observe temperature limits of the measuring system and seals.
3. Define operating pressure: Document the normal working range.
4. Determine maximum pressure: Consider pressure spikes and overload conditions.
5. Select measuring range: Ensure good readability and sufficient pressure reserve.
6. Select measuring element: Define Bourdon tube, diaphragm or another suitable design.
7. Determine process connection: Define thread, flange and connection orientation.
8. Check materials: Match wetted parts to the medium.
9. Define switching points: Specify pressure values clearly.
10. Define switching direction: Consider rising or falling pressure.
11. Define contact function: Determine opening or closing at the respective limit value.
12. Determine number of contacts: Define single limit, min/max or multi-stage monitoring.
13. Select contact type: Choose magnetic snap-action, reed, inductive or electronic contact according to the application.
14. Determine electrical load: Establish voltage, current and load type.
15. Consider AC or DC: Check permissible contact values for the actual circuit.
16. Identify inductive load: Pay particular attention to relay, contactor and solenoid valve coils.
17. Consider an interface relay: Reduce contact load where higher electrical loads are present.
18. Define PLC connection: Match input circuitry and contact technology.
19. Evaluate switching hysteresis: Ensure that process fluctuations do not cause continuous switching.
20. Assess vibrations: Consider mechanical vibration at the measuring point.
21. Assess pressure pulsations: Provide damping where necessary.
22. Select case filling: Consider for dynamic loads or vibrations.
23. Clarify Ex requirements: Select suitable contact and device versions where necessary.
24. Check switching function during commissioning: Test switch-on and reset points in practice.
25. Document the results: Record measuring range, contact type, switching points and electrical circuitry.

Practical example: pump monitoring with a contact pressure gauge

An industrial pump is to supply a process at:

5 … 7 bar

.

The pressure gauge should display the pressure locally.

In addition, two limit values are required:

low-pressure warning at 4 bar

and:

high-pressure warning at 8 bar

Step 1: Two contacts

The contact pressure gauge requires two independently defined switching points.

Step 2: Define switching direction

Contact 1:

pressure falls below 4 bar → warning signal

Contact 2:

pressure rises above 8 bar → warning signal

Step 3: Do not switch a power load directly

The signals are to be transmitted to a PLC.

The control system then handles:

• alarm signalling,
• time delay,
• pump shutdown if necessary.

Step 4: Contact type

A suitable contact technology is selected for the PLC application.

For the WIKA PGS23, for example, the following are available:

• reed contacts,
• electronic contacts

.

Step 5: Check pressure pulsation

The pump produces slight pressure pulsations during operation.

The process pressure fluctuates, for example, by:

±0.2 bar

Do not place switching points directly within an unstable process range

The design must ensure that normal pulsation does not continuously cause limit-value switching.

Step 6: Consider case filling

Because machine vibrations are also present, a liquid-filled pressure gauge version may be useful to stabilize the pointer movement.

Step 7: Commissioning

The pressure is increased and decreased in a controlled manner.

The following are documented:

Test	To be checked
Pressure rises	Upper contact triggers
Pressure falls	Upper contact resets
Pressure falls further	Lower contact triggers
Pressure rises again	Lower contact resets

Result

Reliable operation is achieved not solely by selecting the correct pressure range, but through the interaction of contact type, switching logic, hysteresis, process dynamics and electrical signal processing.

Suitable ICS products for pressure indication and limit switching

WIKA PGS23.100 / PGS23.160 – Bourdon tube pressure gauge with switch contacts

For conventional industrial contact pressure gauge applications, the following model listed by ICS is particularly suitable:

WIKA PGS23.100 / PGS23.160

The device combines:

mechanical on-site pressure indication + electrical switch contacts

ICS specifies the following features, among others

• up to four switch contacts per instrument,
• case filling available for high dynamic pressure loads and vibrations,
• inductive contacts for corresponding applications in hazardous areas,
• contacts for PLC applications,
• optional safety version with solid baffle wall.

Available contact technologies

The following are available for the PGS23:

• magnetic snap-action contacts,
• reed switches,
• inductive contacts,
• electronic contacts.

For PLC applications in particular:

• electronic contacts,
• reed switches

can be used.

Typical applications

ICS lists, among other things:

• process control and regulation,
• plant monitoring,
• switching electrical circuits,
• chemical and petrochemical industries,
• power plants,
• machine building,
• general plant construction.

Further information can be found under WIKA PGS23.100 / PGS23.160 at ICS Schneider.

WIKA PGS43.100 / PGS43.160 – Diaphragm pressure gauge with switch contacts

For applications with other process requirements, ICS also offers the:

WIKA PGS43.100 / PGS43.160

The diaphragm version is particularly interesting for

• low pressure ranges,
• increased overload requirements,
• high-viscosity media,
• contaminated media.

ICS specifies the following for the PGS43, among other things

• indication ranges from 0 … 25 mbar,
• high overload safety up to 10 times the full-scale value, maximum 40 bar,
• up to four switch contacts,
• liquid filling for dynamic pressure loads and vibrations,
• inductive contacts for corresponding hazardous-area applications,
• contacts for PLC applications.

Further information can be found under WIKA PGS43.100 / PGS43.160 at ICS Schneider.

Which contact pressure gauge is suitable?

Application	Suitable solution
Conventional industrial pressure measurement with limit signal	WIKA PGS23.100 / PGS23.160
Local indication plus multiple switching points	PGS23 or PGS43, depending on measuring medium and pressure range
PLC application	Suitable reed or electronic contact version of the PGS23 or PGS43
Strong vibration or dynamic pressure loading	Consider a suitable filled version
Low pressure ranges or high overload requirements	Consider PGS43
High-viscosity or contaminated media	Consider PGS43

An overview can be found under Contact Pressure Gauges at ICS Schneider.

Conclusion

A contact pressure gauge combines two tasks:

display pressure locally

and:

signal an electrical limit value

For reliable operation, it is therefore not sufficient merely to specify:

measuring range + thread

.

The following are also decisive:

• contact type,
• number of switching points,
• switching direction,
• electrical switching capacity,
• AC or DC operation,
• type of connected load,
• switching hysteresis,
• pressure pulsation,
• vibration,
• PLC or relay connection.

Problems arise particularly often when a small limit signal contact is expected to switch an excessively large or electrically unfavorable load directly.

For higher or inductive loads, it is therefore often useful to install an:

interface relay

between the contact pressure gauge and the load.

For a PLC connection, a suitable contact technology can instead transmit the limit signal directly to a digital input.

Hysteresis must not be ignored either.

A switching point in a pulsating process can otherwise lead to continuous contact switching.

For mechanically or hydraulically unstable applications, the following can additionally contribute to stabilization:

• case filling,
• pressure damping,
• PLC-side delay

.

For conventional process applications, the WIKA PGS23.100 / PGS23.160 listed by ICS, with different contact technologies and up to four switching contacts, is a suitable choice.

For low pressure ranges, higher overload requirements, and high-viscosity or contaminated media, the WIKA PGS43.100 / PGS43.160 may be a suitable alternative.

For practical applications:

Determine measuring medium → determine pressure and temperature range → select measuring range → consider overload and pulsation → define switching point → define switching direction → determine number of contacts → select contact type → determine voltage, current and load type → check switching capacity → provide interface relay where necessary → match PLC input → evaluate hysteresis and process fluctuations → consider vibration and case filling → test switching points at rising and falling pressures → document configuration.

FAQ: Selecting a Contact Pressure Gauge Correctly

What is a contact pressure gauge?

A contact pressure gauge combines mechanical on-site pressure indication with one or more electrical limit signal contacts.

What does the switching contact in the pressure gauge do?

It opens or closes an electrical circuit when the instrument pointer exceeds or falls below a preset pressure limit.

What is the difference between a contact pressure gauge and a pressure switch?

In addition to the switching function, a contact pressure gauge provides continuously visible mechanical pressure indication. A pressure switch is primarily intended for electrical limit-value switching.

Can a contact pressure gauge switch a pump directly?

Not in every case. The electrical load must remain within the permissible contact ratings. For larger loads, the pump or its contactor should be switched via a suitable control system or interface relay.

Can a contact pressure gauge switch a solenoid valve directly?

Only if voltage, current, load type and switch-off behavior remain within the permissible contact ratings. Solenoid coils in particular are inductive loads and can generate high voltage spikes when switched off.

What is switching capacity?

Switching capacity describes the electrical load that a contact can safely switch under the specified conditions.

Is specifying the voltage sufficient for selecting the contact?

No. At minimum, current, AC/DC and the type of load must also be considered.

Why is DC often more critical for contacts than AC?

With DC there is no regular natural current zero crossing. An arc that forms when the contact opens may therefore be more difficult to extinguish.

What is an inductive load?

Typical inductive loads include relay, contactor and solenoid valve coils as well as other components with significant inductance.

Why are inductive loads critical?

When switching off, the energy stored in the inductance can generate a high voltage spike and stress the switching contact.

When should I use an interface relay?

When the pressure gauge contact should not directly carry the required load or when additional relay functions are required.

What does switching hysteresis mean?

Switching hysteresis is the difference between the pressure at which the contact switches and the pressure at which it switches back when the pressure moves in the opposite direction.

Why does a contact need hysteresis?

Among other things, it prevents small pressure fluctuations from immediately causing continuous on/off switching.

Is hysteresis the same as measurement accuracy?

No. Measurement accuracy describes the pressure indication. Hysteresis describes the difference between the switch-on and reset points.

Why does a contact pressure gauge chatter?

Possible causes include pressure pulsations, mechanical vibrations, or a switching point that lies too close to the normal fluctuating process pressure.

How can contact chattering be reduced?

Depending on the cause, suitable hysteresis, pressure damping, case filling or time-based evaluation in the PLC can help.

Can a contact pressure gauge have multiple switching points?

Yes. Depending on the device, several contacts are possible. The WIKA PGS23.100 and PGS23.160, for example, can be equipped with up to four switch contacts per instrument.

Can I monitor minimum and maximum with one contact pressure gauge?

Yes. With two appropriately configured contacts, for example, a lower and an upper limit value can be monitored.

Can a contact pressure gauge provide a pre-warning and a shutdown signal?

Yes. With multiple switch contacts, different limits can be defined for pre-warning and subsequent shutdown.

Which contact types are available for the WIKA PGS23?

WIKA and ICS list magnetic snap-action contacts, reed switches, inductive contacts and electronic contacts.

Which contact is suitable for a PLC?

For the WIKA PGS23, electronic contacts and reed switches can be used for PLC applications.

What is a magnetic snap-action contact?

A magnetic snap-action contact is a mechanical limit signal contact with magnetically assisted switching action.

What is a reed contact?

A reed switch uses magnetically actuated contacts in an encapsulated system and, depending on the version, is suitable for corresponding signal applications.

What is an inductive contact?

An inductive contact detects the limit value without physical contact and is used, among other things, for suitable industrial and hazardous-area applications.

Can an inductive contact be connected directly like a conventional switch?

Not necessarily. Depending on the version, suitable evaluation electronics or a switching amplifier may be required.

What is an electronic contact?

An electronic contact generates the switching signal electronically and is particularly suitable for corresponding automation and PLC applications.

Can a contact pressure gauge be used in a hazardous area?

Suitable device and contact versions are available. For the WIKA PGS23, ICS lists inductive contacts for corresponding applications in hazardous areas, for example. However, the complete explosion-protection design must be considered.

Why should a contact pressure gauge be filled?

A case filling can damp pointer movement under vibration and dynamic pressure loads and reduce mechanical stress.

Does filling help against pressure pulsations?

It can damp the visible pointer movement. Strong process pulsations should, however, also be reduced directly at the measuring point where necessary.

What is the correct measuring range for a contact pressure gauge?

The measuring range should represent the normal operating pressure clearly while also taking into account the maximum pressures that can occur and the permissible overload of the specific instrument.

Do I need to consider pressure spikes?

Yes. Short-term pressure spikes can mechanically overload the measuring system even if the normal operating pressure is much lower.

Which contact pressure gauge is suitable for conventional process applications?

The WIKA PGS23.100 or PGS23.160 is listed by ICS for process control, plant monitoring and switching electrical circuits.

What is the WIKA PGS23?

The PGS23 is a Bourdon tube pressure gauge with electrical switch contacts for industrial process applications.

How many contacts can the WIKA PGS23 have?

The PGS23.100 and PGS23.160 versions can be equipped with up to four switch contacts.

Can the PGS23 be used under vibration?

ICS also lists versions with case filling for high dynamic pressure loads and vibrations.

What is the WIKA PGS43?

The PGS43 is a diaphragm pressure gauge with switch contacts for industrial process applications.

When is the PGS43 particularly suitable?

Among other things, for low pressure ranges, increased overload requirements, and high-viscosity or contaminated media.

How low can the indication range of the PGS43 start?

ICS specifies indication ranges starting from 0 … 25 mbar.

How overload-resistant is the PGS43?

ICS specifies high overload safety of up to 10 times the full-scale value, maximum 40 bar, depending on the specific version.

Where can I find contact pressure gauges at ICS Schneider?

An overview can be found under Contact Pressure Gauges at ICS Schneider.

Where can I find the WIKA PGS23 at ICS Schneider?

Further information can be found under WIKA PGS23.100 / PGS23.160 at ICS Schneider.

Where can I find the WIKA PGS43 at ICS Schneider?

Further information can be found under WIKA PGS43.100 / PGS43.160 at ICS Schneider.