The packaging of the sensor, especially often overlooked is its frame, however this will gradually reveal its shortcomings in later use. In the purchase of the transmitter must take into account the future working environment of the sensor, how the humidity, how to install the sensor, there will be strong impact or vibration.

Select output signal pressure

What output signals the sensor needs to get: mV, V, mA, and frequency output digital output, depending on a variety of factors, including the distance between the sensor and the system controller or display, whether there is "noise" or other electronic interference signals. Whether the amplifier, the position of the amplifier, etc. are required. For many OEM devices with short distances between sensors and controllers, the most economical and effective solution for mA output sensors, if you need to amplify the output signal, it is best to use a sensor with built-in amplification. For long-distance transmission or strong electrical interference signals, it is best to use mA output or frequency output.

In environments where RFI or EMI specifications are high, in addition to the need to select mA or frequency output, special protection or filters are also considered. (At present, due to various collection needs, there are many kinds of output signals of pressure sensors on the market, mainly 4-20mA, 0-20mA, 0-10V, 0-5V, etc., but the more commonly used is 4-20mA and 0-10V two kinds, among the output signals I mentioned above, only 2-20mA is two-wire system, we say that the output is several lines without grounding or shielding, the others are three-wire system).

Select excitation voltage

The type of output signal determines how the excitation voltage is selected. Many amplification sensors have built-in voltage regulation, so their supply voltage range is large. Some transmitters are quantitatively configured and require a stable operating voltage. Therefore, a working voltage that can be obtained determines whether or not to use a sensor with a regulator. When selecting a transmitter, it is necessary to consider the operating voltage and system cost.

Need to have interchangeable sensors?

Determine if the required sensor can accommodate multiple use systems. Generally speaking, this is very important. Especially for OEM products. Once the product is delivered to the customer, the cost of the customer‘s calibration is considerable. If the product is interchangeable, even changing the sensor used will not affect the overall system.

other

After confirming some of the above parameters, we must also confirm the process connection interface of your pressure sensor and the supply voltage of the pressure sensor; if it is used in special occasions, the explosion protection and protection level should also be considered.

Pressure sensor daily use and maintenance

Prevent dross from depositing in the conduit and contact the sensor with corrosive or superheated media.

When measuring the gas pressure, the pressure tap should be opened at the top of the process pipe, and the sensor should also be installed in the upper part of the process pipe so that the accumulated liquid is easily injected into the process pipe.

When measuring the pressure of the liquid, the pressure tap should be opened on the side of the process piping to avoid depositing slag.

The pressure guiding tube should be installed where the temperature fluctuations are small.

When measuring the pressure of the liquid, the installation position of the sensor should avoid the impact of the liquid (water hammer phenomenon) to avoid damage to the sensor overpressure.

When freezing occurs in winter, sensors installed outdoors must take anti-freeze measures to prevent the liquid in the pressure-inlet from expanding due to the volume of ice, resulting in loss of the sensor.

When wiring, pass the cable through the waterproof joint or the coil and tighten the seal nut to prevent rainwater and the like from leaking into the transmitter housing through the cable.

When measuring steam or other high-temperature medium, it is necessary to add a condenser such as a buffer tube (coil), and the operating temperature of the sensor should not exceed the limit.