Know 7 Points in Pressure Sensor Connection and Installation
There are many problems to be aware of in pressure sensor connection and
Installation. The pressure sensor itself is a strong, durable and
reliable electromechanical product, but in order to ensure the
measurement accuracy. This article summarizes the issues that should be
considered when using pressure sensors.
1. Pressure sensor cable
In any case, the power cable and control line should be twisted together to a degree of 50 rpm / meter. If the signal line of the pressure sensor needs to be extended, use a special sealed cable junction box. If the junction box is not used, but the cable and the cable are directly butted (soldered end), pay a special attention to sealing the moisture. Check the insulation resistance after connection, and must meet the standard (2000 ~ 5000M). If it is necessary, the pressure sensor should be recalibrated. If the signal cable is long and high measurement accuracy is required, use a cable compensation circuit with the relay amplifier.
2. Pick up and put down the pressure sensor with care
The pressure sensor should be handled with care. In particular, for a small-capacity sensor whose elastomer is made of alloy aluminum, any impact or drop may cause great damage to its metering performance. For large-capacity pressure sensors, in general, it has a large weight. Therefore, it is required to use appropriate lifting equipment (such as chain hoists, electric hoists, etc.) when transporting and installing. When installing, the base mounting surface of the pressure sensor should be flat and clean without any oil film or colloid film. The mounting base itself should have sufficient strength and stiffness, which is generally required to be stronger than the strength and stiffness of the pressure sensor itself.
3. Pressure sensor electrical connection
For electrical connections, such as signal cables of pressure sensors, do not place them in parallel with high-voltage power cables or control lines (that is, do not place the signal cable of the pressure sensor and the strong power supply cable and control line in the same pipe. If they must be placed in parallel, the distance between them should be kept above 50 CM and the signal wires should be covered with metal tubes.
4. Baffle setting
Set some baffles around the pressure sensor as far as possible. If possible, cover the pressure sensor with a thin metal plate. This prevents debris from contaminating the pressure sensor and some other operating equipment. Because this kind of fouling often interferes with the equipment operation and affects the measurement accuracy.
5. Prevent pressure sensor overload
Although the pressure sensor has a certain overload capacity, the overload of the pressure sensor should be prevented during the installation of the measurement system. It should be noted that even a short overload may cause permanent damage to the pressure sensor. In normal operation, the pressure sensor should generally be set with mechanical components for overload protection. If the pressure sensor is fixed by a screw, it should have a certain tightening torque, and the screw should have a certain screw in thread depth. In general, the fixed screw should use a high-strength screw.
6. Pressure sensor circuits setting
Shielded cables should be used for all wires leading to display circuits or lead from the circuit. The connection and grounding point of the shielded wire should be reasonable. If it is not grounded through the mechanical frame, it is grounded externally, but the shielded wires are not grounded after being connected to each other and are floating. It should be noted that if there are three pressure sensors, use the fully parallel connection. Although the pressure sensor itself is a 4-wire system, it is replaced by a 6-wire connection in the junction box.
The readout circuit of the pressure sensor output signal should not be placed in the same cabinet with the contactor that generates strong interference and the device that generates heat. If this is not guaranteed, place a baffle between them to isolate them and place a fan inside the box. The electronic circuit used to measure the output signal of the pressure sensor should be equipped with a separate power transformer as much as possible, instead of sharing the same main power supply with devices such as contactors.
7. Others
The pressure sensor should be electrically bypassed with hinged copper wires (approximately 50 square millimeters cross-sectional area) to protect them from welding current or lightning strikes. Pressure sensors must avoid strong thermal radiation during use, especially strong heat radiation on one side.
1. Pressure sensor cable
In any case, the power cable and control line should be twisted together to a degree of 50 rpm / meter. If the signal line of the pressure sensor needs to be extended, use a special sealed cable junction box. If the junction box is not used, but the cable and the cable are directly butted (soldered end), pay a special attention to sealing the moisture. Check the insulation resistance after connection, and must meet the standard (2000 ~ 5000M). If it is necessary, the pressure sensor should be recalibrated. If the signal cable is long and high measurement accuracy is required, use a cable compensation circuit with the relay amplifier.
2. Pick up and put down the pressure sensor with care
The pressure sensor should be handled with care. In particular, for a small-capacity sensor whose elastomer is made of alloy aluminum, any impact or drop may cause great damage to its metering performance. For large-capacity pressure sensors, in general, it has a large weight. Therefore, it is required to use appropriate lifting equipment (such as chain hoists, electric hoists, etc.) when transporting and installing. When installing, the base mounting surface of the pressure sensor should be flat and clean without any oil film or colloid film. The mounting base itself should have sufficient strength and stiffness, which is generally required to be stronger than the strength and stiffness of the pressure sensor itself.
3. Pressure sensor electrical connection
For electrical connections, such as signal cables of pressure sensors, do not place them in parallel with high-voltage power cables or control lines (that is, do not place the signal cable of the pressure sensor and the strong power supply cable and control line in the same pipe. If they must be placed in parallel, the distance between them should be kept above 50 CM and the signal wires should be covered with metal tubes.
4. Baffle setting
Set some baffles around the pressure sensor as far as possible. If possible, cover the pressure sensor with a thin metal plate. This prevents debris from contaminating the pressure sensor and some other operating equipment. Because this kind of fouling often interferes with the equipment operation and affects the measurement accuracy.
5. Prevent pressure sensor overload
Although the pressure sensor has a certain overload capacity, the overload of the pressure sensor should be prevented during the installation of the measurement system. It should be noted that even a short overload may cause permanent damage to the pressure sensor. In normal operation, the pressure sensor should generally be set with mechanical components for overload protection. If the pressure sensor is fixed by a screw, it should have a certain tightening torque, and the screw should have a certain screw in thread depth. In general, the fixed screw should use a high-strength screw.
6. Pressure sensor circuits setting
Shielded cables should be used for all wires leading to display circuits or lead from the circuit. The connection and grounding point of the shielded wire should be reasonable. If it is not grounded through the mechanical frame, it is grounded externally, but the shielded wires are not grounded after being connected to each other and are floating. It should be noted that if there are three pressure sensors, use the fully parallel connection. Although the pressure sensor itself is a 4-wire system, it is replaced by a 6-wire connection in the junction box.
The readout circuit of the pressure sensor output signal should not be placed in the same cabinet with the contactor that generates strong interference and the device that generates heat. If this is not guaranteed, place a baffle between them to isolate them and place a fan inside the box. The electronic circuit used to measure the output signal of the pressure sensor should be equipped with a separate power transformer as much as possible, instead of sharing the same main power supply with devices such as contactors.
7. Others
The pressure sensor should be electrically bypassed with hinged copper wires (approximately 50 square millimeters cross-sectional area) to protect them from welding current or lightning strikes. Pressure sensors must avoid strong thermal radiation during use, especially strong heat radiation on one side.