Power requirements:

Instrument power supply should be used, and there should be no spikes in the power supply. Switch type power supply should be used with caution, especially for smart meters with built-in switch power supply, otherwise it is easy to self excite and damage the transmitter.

The power supply should be grounded with a shielding layer to prevent lightning strikes, and the crimping nut should be tightened to ensure air tightness and moisture resistance.

The supply voltage is usually 24VDC (18V~36VDC), and the load should be ≥ 500 Ω (24VDC).

Installation and wiring:

Before installation, it should be confirmed that the temperature change range of the measuring point is within the measurement range of the transmitter, and the power supply should be confirmed to meet the standards before powering on.

When wiring, special attention should be paid to the distinction between ordinary type and intrinsic safety type. Ordinary type cannot be installed in hazardous areas, while intrinsic safety type can be installed in hazardous areas.

The wiring of the safety spark circuit (input signal line) must be insulated or shielded wires, and isolated from the wiring of non safety spark circuits to avoid mutual contact.

When wiring explosion-proof instruments with safety spark circuits, they must not be connected incorrectly and carefully checked for short circuits or incorrect connections.

The input of the thermal resistance transmitter is a three wire system, and the line resistance of each connecting wire should be equal and within the same ambient temperature.

The power wiring requires the use of copper wires with a cross-sectional area of at least 0.5mm ², and U-shaped clips should be installed at the wire interface. If conditions permit, soldering can be added to ensure the reliability of the connection and to prevent wire burrs.

Usage environment:

When measuring temperature, try not to exceed 70% of the full range, let alone use beyond the range.

If high temperature (100 ℃) or low temperature (5 ℃) needs to be measured, high-temperature resistant filling materials (such as silicone rubber) should be used to isolate the sensor chamber from the junction box and seal it to prevent the junction box from overheating and burning out the transmitter or sensor due to low temperature condensation inside.

The working environment of the transmitter should be kept clean to avoid excessive dirt or salt residue causing poor insulation and affecting measurement accuracy.

Calibration and maintenance:

The transmitter should be calibrated every 6 months. For thermocouple types that have not undergone current internal corrections, it is recommended to choose the appropriate range to ensure their accuracy.

When wiring, the surface of the wire must be cleaned of the oxide layer.

During regular inspections, in order to accurately read data, a digital voltmeter should be connected between the output terminals for measurement, and the safety spark return line should not be removed.

In principle, it is not allowed to disassemble the components of the safety spark circuit and replace the instrument wiring for explosion-proof instruments. If replacement is necessary, it should be carried out according to explosion-proof requirements.

Special installation requirements:

The sensor should be able to be inserted into the center position of the temperature field to be measured.

High temperature measurement is generally installed vertically. If installed on the side, it will cause deformation and damage to the protective tube, and the equipment needs to be equipped with a protective bracket.

For measurements with stirring disturbances, a reinforced tube is generally required, and the sensor is inserted into the measurement site from the reinforced tube; If a faster response time is required, the sensor part (i.e. the end of the sensor protection tube) can be slightly exposed.

The measurement of flow velocity in situations such as pipelines should not only consider the impact force of the fluid, but also the vortex vibration damage generated by the fluid. The protective pipe not only needs to have a certain structural strength, but the installation method is also important, such as installing diagonally along the flow direction, or inserting it into the pipeline at a right angle to the flow direction.