What precautions should be taken when using a manhole level gauge?

　　 Manhole level gauge What matters should be noted?

　　Among conventional level gauges, differential pressure transmitters, radar level meters, magnetostrictive level meters, and float-type level meters are widely used; however, each is subject to the limitations of its underlying measurement principle. So, what considerations should be taken into account when selecting a manhole level gauge?

　　What precautions should be taken when using a manhole level gauge?

　　1. Do not apply a voltage exceeding 36 V to the transmitter; otherwise, the transmitter may be damaged.

　　2. Do not allow hard objects to come into contact with the diaphragm of the well‑level gauge, as this may damage the isolation diaphragm.

　　3. The medium measured by the level sensor must not be allowed to freeze; otherwise, the sensor element’s isolation diaphragm will be damaged, leading to failure of the transmitter. If necessary, a temperature‑protection device should be installed to prevent freezing.

　　4. When measuring steam or other high‑temperature media, the temperature should not exceed the operating temperature of the level sensor; if it does, the sensor’s rated temperature limit is exceeded. Under adverse temperature conditions, a heat‑dissipation device must be used.

　　5. When measuring steam or other high‑temperature media, a heat‑dissipating tube should be used to connect the level sensor to the pipeline, allowing the pressure in the pipeline to be transmitted to the instrument. If the medium being measured is steam, an appropriate amount of water should be injected into the heat‑dissipating tube to prevent superheated steam from coming into direct contact with the level sensor and damaging the transmitter.

　　6. During the pressure transmission process of the well‑type level gauge, the following points should be observed:

　　(1) The connection between the liquid-level sensor and the heat pipe is watertight.

　　(2) Before use, if the valve is closed, open it very carefully and slowly to prevent the measured medium from directly冲刷 (flushing) the sensor diaphragm and causing damage.

　　(3) The pipeline must remain unobstructed; sediment and sand within the pipe may be ejected, damaging the sensor diaphragm.

　　What are the technical specifications of a manhole level gauge?

　　1. Measurement range: 200–15,000 mm (for level gauges exceeding 6,000 mm in length or where transportation constraints prohibit exceeding this length, segmented fabrication may be arranged).

　　2. Display accuracy: ±10 mm.

　　3. Working pressure: 6.3, 10.0, 16.0, 25.0 MPa.

　　4. Medium temperature: -20℃ to 450℃.

　　5. Medium density: ≥ 0.5 g/cm³.

　　6. Medium density difference: ≥ 0.15 g/cm³ (for interface measurement).

　　7. Medium viscosity: ≤0.4 Pa·s.

　　8. Process connection: DN20/25 PN1.0; other standards can be manufactured upon customer request.

　　9. Wetted material: 316SS, 316L, etc. (selected according to the medium’s chemical properties and the operating temperature and pressure).

　　10. Manhole level gauge Float material: 316SS, 316L, titanium, etc.