Can every pressure transmitter be used to measure any medium?

No, customers must check the materials indicated in the data sheet when using them. (No, customers must refer to the material description in the sample before use)

Can the pressure transmitter still work in the event of a power outage?

Can't

Will the pressure transmitter function properly when the voltage is slightly lower than the specified ground voltage requirement? For example: the specified low voltage of a pressure transmitter is DC 10 V, but the user system can only provide DC 9 V. In this case, can the pressure transmitter work normally?

Before reaching the upper pressure limit value, the pressure transmitter can still provide the correct output signal, but if the pressure exceeds the upper limit value, the output signal will remain at the maximum value because the voltage is too low and the power supply cannot provide sufficient output. (Depending on the situation, when working under undervoltage, after the working pressure reaches a certain zero point, the output signal remains constant and does not become larger as the pressure increases, because the low supply voltage cannot provide full-scale output)

Can the connector be changed?

Electrical connections cannot be changed.

Can a 3-wire transmitter operate in a 2-wire configuration? (Can a 3-wire transmitter be used in 2-wire applications?)

Can't

Can I switch between 4 to 20 mA and 0 to 10 V?

No, the output signal range is determined by the user when purchasing and cannot be changed.

What factors can cause zero point drift?

Electrical component aging, temperature and load cycles (electrical component aging, temperature changes and load operating conditions).

At what pressure does a diaphragm rupture?

The rupture pressure of each diaphragm is different, please refer to the data sheet of each product for details.

What solutions are available to avoid pressure spikes?

For pressure peaks, we recommend the use of process connections with 0.6mm EDM flow channels. The use of process connections with 0.3mm EDM flow channels is more effective. (For pressure peaks, it is recommended to use a 0.6mm damping design. The 0.3mm design works better under certain conditions)

What are mechatronic measuring instruments?

Mechanical measuring instruments are instruments that integrate electronic components or components and have purely mechanical on-site display functions and additional electrical output signals or switching functions. Such instruments allow the operator to reliably read measured values ​​even if the power supply or the measuring signal is disturbed or interrupted.

What is the Hall effect?

When a current passes through a conductor perpendicular to the external magnetic field, a voltage proportional to the strength of the magnetic field (ie, Hall voltage) is generated between the two end surfaces of the conductor perpendicular to the direction of the magnetic field and current.

What functions does the Hall sensor have in the intelliGAUGE/ intelliTHERM series instruments?

The pointer of the intelliGAUGE/ intelliTHERM meter is equipped with a permanent magnet. The permanent magnet can generate a magnetic field that affects the Hall sensor, and can rotate with the pointer around the pointer axis. When the pointer rotates, the angle of the magnetic field lines generated by the two stages of the permanent magnet will change, and the Hall sensor will also produce corresponding changes under the influence of the magnetic field. Given this, we can measure the rotation angle of the Hall sensor under the influence of a magnetic field. Since the magnetic field intensity acting on the Hall sensor is different at different magnetic field line angles, the Hall sensor will generate a Hall voltage proportional to the rotation angle (ie, pressure) of the pointer.

What do PGT and PGS stand for?

PGT (Pressure Gauge Transmitter) and PGS (Pressure Gauge Switch) are both mechanical and electronic pressure measuring instruments. Both can display pressure measurement values ​​without an external power supply. PGT can generate electrical output signals, while PGS can provide electronic switching functions.

What is a magnetically assisted micro switch electrical contact (type 821)?

The magnetically assisted electrical contacts adopt mechanical working principles and can switch loads up to 30W50VA. This electrical contact can output a signal before or after the actual value pointer movement. When the measured value reaches the set value, a permanent magnet mounted on the bracket attracts the contact pin on the movable contact arm, thus closing the circuit. Due to the magnetic force of the magnet, the magnetically assisted electrical contact has good resistance to vibration. The permanent magnet attracts the contact arm until the restoring force of the measuring element exceeds the magnetic force and the contact spring opens.

What is a sliding electrical contact (Type 811)?

The sliding electrical contacts adopt a mechanical working principle and can switch loads up to 10W 18VA.

What is an electronic electrical contact (type 830.E)?

Electronic electrical contacts are usually used with non-contact slot sensors and are suitable for oil-filled pressure gauges, especially for low voltage and small DC current load applications, such as signal inputs to PLCs (Programmable Logic Controllers).

What is an inductive electrical contact (Type 831)?

According to EN50227, inductive electrical contacts of pointer instruments are usually used together with non-contact distance sensors (proximity sensors). The input signal can be determined by looking at the flag-shaped mark that moves as the pointer of the actual value within the electromagnetic field range of the proximity switch turns. Inductive electrical contacts are often used in hazardous areas.

What is a reed electrical contact (Type 851)?

Reed electrical contacts are typically used to switch smaller voltages and currents and are sealed in the device with an inert gas so corrosion will not occur. In addition, this electrical contact has high reliability and low contact resistance, and is widely used, such as PLC applications, signal conversion of measuring instruments, signal lights, sound signal transmitters, etc.

What is an isolation amplifier?

Isolating amplifiers can be used to transmit digital signals from hazardous areas. The signal transmitter used in the amplifier can be a sensor according to DIN 19234 (NAMUR) or a mechanical electrical contact. The inputs must be isolated from the outputs and power supply in accordance with DIN EN50020, while the outputs and power supply must be isolated from each other in accordance with DIN EN50178.

What does toggle function mean?

The switching function refers to opening or closing a circuit. Normally closed contacts (NC, represented by 2) break the circuit when pressure rises (clockwise direction), and normally open contacts (NO, represented by 1) close the circuit when pressure rises (clockwise direction).

What are transfer switch electrical contacts?

When the set value is exceeded, the electrical contacts open (NC) one circuit and close (NO) the other circuit. The transfer switch electrical contacts are represented by the number 3 (SPDT).

What is NAMUR?

NAMUR is the abbreviation of "Normenausschuss Mess- und Regeltechnik" (Standards Committee for Measurement and Control).

What is ATEX?

ATEX is often used to refer to the EU ATEX directive. The name comes from the French abbreviation of "Atmosphere explosible". This directive currently includes two directives in the field of explosion protection, namely the ATEX Equipment Directive 94/9/EC and the ATEX Workplace Directive 99/92/EC.

Which standard regulates electrical contact instruments?

Sliding and magnetically assisted electrical contacts for mounting on pressure gauges with a case diameter of 100 mm and thermometers with a case diameter of 160 mm are specified by DIN 16085.

Can the zero point of the PGT series pressure gauge be set by the user?

For most pressure gauges, the user can reset the zero point at any time according to the requirements of the field application. For specific steps to reset the zero point, please refer to the operating instructions. Note: Once the zero point changes, the pressure/temperature range will also shift positively/negatively. Normally, there is no need to reset the zero point of the pressure gauge.

Can the range of PGT series pressure gauge be set by the user?

The user cannot change the range. However, for electronic pressure gauges, we can provide products in any range according to customer requirements, even non-linear scales, and we can also provide products that support square wave signals or square root signals.

When to use a diaphragm seal?

For users, the use of diaphragm seals enables various measuring instruments to meet demanding applications.

Example:

- The medium is corrosive and the pressure measuring element itself (e.g. the interior of the spring tube) is not sufficiently protected against this medium.

- The media are highly viscous and fibrous, causing dead corners and compression in the bore of the pressure measuring instrument (pressure flow channel, spring tube), thus causing measurement problems. The medium has a tendency to crystallize or polymerize.

- The medium temperature is very high, causing the pressure measuring instrument to heat up rapidly, which in turn leads to high temperature errors in pressure measurement (that is, the measured pressure displayed on the measuring instrument does not match the actual value), and may even cause the temperature to exceed the upper limit of the thermal load of the instrument components.

- The pressure measuring point is located in an inaccessible location. Due to space constraints, pressure measuring instruments cannot be installed or are difficult to read. In this case, the user can install the pressure gauge in an easily visible location by installing a diaphragm seal and using a longer capillary tube.

-The product production process and production equipment have strict hygiene requirements. In this case, blind spots in the measuring instrument and accessories must be avoided.

- The media is toxic or harmful to the environment. In this case, it is necessary to prevent the medium from leaking into the atmosphere or environment. For safety and environmental protection reasons, appropriate protective measures must be taken.

What is a diaphragm seal?

The diaphragm seal is already installed on the existing connection. Typically, the connection includes a tee integrated into the pipe, a welded sleeve welded to the pipe, a process reactor or a tank.

What is an in-line seal?

In-line diaphragm seals are ideal for flowing media. By fully integrating the seal into the process pipe, measurements are not affected by any turbulence, corners, dead ends or other obstructions in the flow direction. This type of seal not only prevents the flow of media from being hindered, but also improves the self-cleaning function of the measuring chamber. The diaphragm seal consists of a cylindrical cover with a welded thin-walled cylindrical diaphragm, which eliminates the need for special measuring point connections. In addition, in-line diaphragm seals also have different nominal widths and can be applied to pipes of different cross-section sizes. For flange connections PN 6 to PN 400, the seal has an upper pressure range of up to 400 bar and a nominal temperature limit of +400 °C.

What is a capsule diaphragm seal?

This type of seal can be inserted directly into the medium and is therefore particularly suitable for non-homogeneous media. Compared to other diaphragm seals, this type of seal requires particularly little space and the pressure can be determined "at one point". The seal consists of an oval tube with one end closed, a pressure sensor and a joint part welded to the tube. To tighten the seal, we mount the sensor to an accessory and connect the seal to the measuring point using internal and external threads.

Why is the upper temperature limit of the PTFE version only 260 °C and the upper pressure limit only 100 bar?

PTFE will flow so the maximum pressure and temperature are reduced.

What is the thickness of the PTFE coating on the diaphragm?

0.15 mm

What is the thickness of the PFA coating on the separator?

0.15 mm

How to cross-reference the ISO 7005-1 standard with the EN and ASME standards for flanges?

DN 50 ISO PN 20 = DN 2" Class 150 ASME B16.5

DN 50 ISO PN 50 = DN 2" Class 300 ASME B16.5

DN 80 ISO PN 20 = DN 3" Class 150 ASME B16.5

DN 80 ISO PN 50 = DN 3" Class 300 ASME B16.5

DN 50 ISO PN 10-40 = DN 50 PN 10-40 EN 1092-1

DN 80 ISO PN 40 = DN 80 PN 40 EN 1092-1

What is the accuracy of a diaphragm seal system?

First, accuracy depends on the connected measuring instrument (e.g., a pressure gauge connected with an accuracy of 1.0 will provide a sealing system accuracy of 1% at reference conditions). Under optimal conditions, the accuracy of pressure seals can reach 0.1%. In addition, the accuracy of the sealing system is also affected by temperature, and the specific degree of influence can be calculated through the DSC program (Diaphragm Seal Calculation Program).

Which diaphragm seals are EHEDG certified?

Types 990.24, 990.50, 990.51, 981.50 and 981.51 are EHEDG approved.

Why use a fluid-filled pressure gauge?

The filling liquid provides damping for the moving parts within the watch case, which not only prevents damage caused by vibration but also reduces wear on the moving parts.

What should you do if the temperature of the medium in a fluid-filled pressure gauge exceeds 100°C?

You can use a pressure gauge condenser or capillary tube as an additional cooling element to reduce the medium temperature.

Why do some pressure gauges have a maximum ambient temperature of only 60°C?

If the display window of the pressure gauge is made of safety glass, the maximum ambient temperature must not exceed 60°C. Safety glass is made by gluing two glass disks together with foil. Once the temperature exceeds 60°C, the foil can bubble, making the display window scale inaccurate.

Under what circumstances must the CE mark be stamped on the dial?

When the measuring instrument complies with the Pressure Equipment Directive (PED; >= 200 bar), the EMC Directive (e.g. intelliGAUGE) or the Low Voltage Directive (e.g. 821 or 851 contacts).

What does the "little yellow joystick" on the pressure gauge housing do?

Pressure gauges with pressure ranges below 2.5 MPa are usually equipped with a filler plug with a small operating lever. These yellow levers are delivered closed and must be opened during assembly to prevent pressure from building up in the container. The presence of pressure in the vessel may cause unacceptable deviations in the pressure gauge.

What is the difference between a standard pressure gauge and a safety pressure gauge?

The safety version (code S3, EN837 compliant) has the following features: 1. An additional solid baffle is welded between the dial and the measuring system; 2. The rear wall of the case can be completely separated. 3. Windows are usually made of laminated safety glass. When pressure builds up in the watch case (for example, if a spring tube ruptures), the back wall of the case will pull away from the case under pressure, allowing the pressure to be completely released through the back wall. Pressure is not released through the window, thus preventing personal injury from flying glass. Among WIKA products, these instrument dials are specially marked with a rounded "S".

Why is the pressure difference not allowed to fall below 1/6 of the full scale value in a Type 7 differential pressure gauge with spring tube?

For the Type 7 differential pressure gauge, the static pressure is the same as the full-scale value at an output rotation angle of 270°. If the static pressure is 1 MPa and the expected pressure difference is 0.1 MPa, the angle between the two ends of the differential pressure gauge is approximately 27°. Therefore, to ensure the accuracy of the differential pressure gauge reading, the pressure differential should not be less than 1/6 of the full scale (output rotation angle is approximately 45°).

What happens when a Type 7 differential pressure gauge with a synthetic rubber isolating diaphragm is operated at an ambient temperature lower than specified in the data sheet?

In this case, the accuracy of the differential pressure gauge will be significantly reduced because the diaphragm (whether made of FPM/FKM or NBR) will harden in a low temperature environment.

What are the functions of a single valve group?

The pressure balance valve is installed upstream, which can achieve pressure load balance between the positive pressure side and the negative pressure side, avoid unilateral overpressure load during the startup and operation of the instrument, and can also perform zero-point inspection during the operation of the instrument.

What are the functions of the three-valve manifold?

The pressure balance valve is installed at the bottom of the differential pressure gauge, which can achieve pressure load balancing on the positive pressure side and the negative pressure side, avoid unilateral overpressure load during the startup and operation of the instrument, and can also perform zero-point checks during the operation of the instrument.

What is the function of a four-valve or five-valve manifold?

These pressure equalization valves (with integrated shut-off valve, exhaust valve and ventilation valve) not only allow the pressure gauge to be vented on one or both sides, but also to drain the supply line.

Why are types 736.11 and 736.51 generally not suitable for corrosive media?

When used in a low pressure (negative pressure side) environment, corrosive media will enter the interior of the display case and corrode components such as the dial (AI), pointer (AI), and display window, so this model can only be used on the positive pressure side. However, the internal structure of the capsule pressure gauge is made of stainless steel and can be used in corrosive media.

How does the measuring system for a type 7 differential pressure gauge with diaphragm operate above full-scale values?

Whether used on the positive pressure side or the negative pressure side, the maximum safe overpressure of the differential pressure gauge should not exceed the maximum working pressure (PN40, PN100, PN250 and PN400). A metal measuring element can usually be used to support the diaphragm surface to ensure that safe overpressure does not exceed the maximum working pressure. Pressures within the permissible overpressure range do not cause any lasting damage to the measuring system.

What is NAMUR?

NAMUR is the abbreviation of "Normenausschuss Mess- und Regeltechnik" (Standards Committee for Measurement and Control).

Which instrument with a small measuring range is suitable for measuring liquid pressure?

Diaphragm pressure gauges with measuring pressures above 1.6 kPa are suitable for measuring liquid pressure (self-draining via the pressure chamber).

What is accuracy?

Accuracy is the error limit expressed as a percentage of range.

When should a flow restrictor be used?

Use in the event of pressure spikes or sudden increases and decreases in pressure.

Are the measurement results of relative pressure measuring instruments affected by altitude?

There is no effect because the measurement result is always the pressure difference from the environment being measured.

What is CNG?

CNG is the abbreviation of Compressed Natural Gas, that is, natural gas (main component is methane) is compressed in high-pressure cylinders for storage and transportation.

What is LNG?

LNG is the abbreviation of liquefied natural gas, which means natural gas (main component methane) is liquefied through low temperature and relatively low pressure and stored and transported in low-temperature storage tanks.

What is LPG?

LPG is the abbreviation of liquefied petroleum gas (the main components are propane and butane), which is petroleum gas refined from crude oil and liquefied at relatively low pressure. Usually LPG is also called Autogas.