Compatibility between measuring medium and material

Medium type: It is necessary to clarify whether the measured medium is liquid, gas, or vapor, and confirm whether it contains corrosive components.

Material selection:

Spring tube: Copper alloy suitable for non corrosive media; Stainless steel is suitable for weakly alkaline or corrosive media.

Joint and shell: Carbon steel has low cost and is suitable for dry and non corrosive environments; Stainless steel is rust resistant and corrosion-resistant, suitable for humid or corrosive environments.

Special requirement: If the medium has high viscosity, is prone to crystallization, or has strong corrosiveness, a diaphragm type resistance remote pressure gauge should be selected to protect the sensor through a diaphragm isolator.

Measurement range and accuracy

Range selection:

Static load: Measure 1/3 to 3/4 of the upper limit value.

Fluctuating load: 1/3 to 2/3 of the measurement upper limit value.

Avoid overloading damage caused by too small a range, or accuracy degradation caused by too large a range.

Accuracy level: usually 1.6, higher precision models can be selected for precision scenes.

environmental adaptability

Temperature range: -40 ℃~60 ℃.

Humidity and vibration: Relative humidity ≤ 85%, shock resistant type should be selected for vibration or medium pulsation.

Protection level: Choose IP65 or higher protection level according to the working conditions.

Signal output and connection

Output signal: The resistance value changes and needs to be used in conjunction with the display instrument.

Wiring method: Adopting a three wire connection system to reduce the impact of wire resistance on measurement; When leaving the factory, the external resistance value should be marked and adjusted according to the actual wire resistance.

Additional features

On site indication: The larger the diameter of the dial, the clearer the reading, making it suitable for long-distance observation.

Anti interference capability: It is recommended to use shielded cables and single ended grounding for long-distance transmission to reduce electromagnetic interference.

2、 Precautions for use

Installation and Debugging

Vertical installation: Ensure that the instrument is placed vertically to avoid reading errors caused by tilting.

Avoid overload: The measured pressure should not exceed 150% of the range to prevent deformation of the elastic components.

Initial calibration: After installation, zero and full calibration are required to ensure measurement accuracy.

Maintenance and Care

Regular cleaning:

Prevent dust from entering the meter and avoid oxidation or poor contact of movable contacts.

Wipe the sliding wire resistor and contacts with alcohol to maintain stable signal transmission.

Check contact wear: Check the contact status every six months, and replace it if it is severely worn.

Rinse the measurement chamber: When the medium is prone to crystallization, regularly rinse to prevent blockage.

troubleshooting

Signal jitter:

Check if the sliding contact is oxidized and polish the surface of the contact with sandpaper.

Test the insulation resistance of the circuit and eliminate short circuits or open circuits.

Linearity deviation:

Calibrate the zero/full adjustment screw and adjust the output resistance range.

Check if the elastic components have undergone plastic deformation and replace them if necessary.

Large distance error:

Control the total resistance of the circuit to reduce voltage drop.

Use shielded cables and single ended grounding to improve anti-interference ability.

safe operation

Do not disassemble under pressure: Before disassembly, the pressure must be released to prevent the medium from spraying out and injuring people.

Avoid mechanical impact: prevent damage to the instrument casing or internal components, which may affect measurement accuracy.

Replacement and verification: If a part is damaged or the pressure measurement range needs to be changed, it needs to be rechecked and marked, and accessories cannot be replaced at will.