Industrial Measurement Instruments Frequently Asked Questions (FAQ)

Compiled by DOWESTON technical team | 2026-07-26

In actual industrial measurement applications, users often encounter various technical problems. Combining many years of industry experience, the DOWESTON technical team has compiled the following 20 common technical questions and answers, covering pressure measurement, electrical contacts, transmitters, mechanical and electronic instruments and other fields to help engineers quickly solve on-site problems.

1. What solutions can be used to avoid pressure spikes?

For pressure peaks, a 0.6mm or 0.3mm damping design is recommended.

2. What factors can cause zero point drift?

Electrical component aging, temperature and load cycling.

3. Can it switch between 4 to 20mA and 0 to 10V?

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

4. Can 3-wire transmitters be used in 2-wire applications?

Cannot.

5. Can the connector be changed?

Electrical connections cannot be changed.

6. What is an inductive electrical contact (Type 831)?

According to EN 50227, 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.

7. 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).

8. What is a sliding electrical contact (Type 811)?

The sliding electrical contacts work mechanically and can switch loads up to 10 W 18 VA.

9. What is a magnetically assisted electrical contact (type 821)?

The magnetically assisted electrical contacts work on a mechanical principle and can switch loads up to 30 W 50 VA.

10. 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 measurements without an external power supply. PGT can generate electrical output signals, while PGS can provide electronic switching functions.

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

A permanent magnet is mounted on the pointer of the intelliGAUGE/intelliTHERM meter. 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.

12. 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.

13. 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.

14. Can the zero point of 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.

15. 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 in DIN 16085.

16. What are transfer switch electrical contacts?

When the set value is exceeded, the electrical contacts open one circuit and close the other. The transfer switch electrical contact is represented by the number 3 (SPDT).

17. 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).

18. 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 EN 50020, while the outputs and power supply must be isolated from each other in accordance with DIN EN 50178.

19. What is a reed switch electrical contact (Type 851)?

Reed switch 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.

20. Why use a liquid-filled pressure gauge?

Filling the watch with liquid can provide damping for the moving parts in the watch case, which not only prevents damage caused by vibration but also reduces wear on the moving parts.

The above technical questions and answers are compiled by the DOWESTON technical team. If you have more