5. What kind of output signal is needed?
For the pressure transmitters, there are mV, V, mA and frequency output digital output signals. The choice of output depends on various factors, including the distance between the transmitter and the system controller or display; whether there is "noise" or other electronic interference signals or not and whether the amplifier, the position of the amplifier, etc. are required.
For many OEM devices with short distances between the transmitter and the controller, the most economical and effective solution is to use mA output sensors. If you need to amplify the output signal, it is best to use a pressure transmitter with built-in amplification. For long-distance transmission or strong electrical interference signals situation, it is best to use mA output or frequency output. In environments where RFI or EMI specifications are high, in addition to select mA or frequency output, special protection or filters are also considered. (Because of various acquisitions, there are many kinds of output signals of pressure transmitters on the market, mainly 4...20mA, 0...20mA, 0...10V, 0...5V, etc., but 4...20mA and 0...10V are common. Among the output signals I mentioned above, only 4...20mA is two-wire system, which excludes round or shielded wire. Others are three-wire system)
6. Is there a need for interchangeable pressure transmitters?
Determine if the transmitters you need can accommodate multiple systems. Generally speaking, this is very important, especially for OEM products. Once the product is delivered to the customer, the cost of the re-calibration is considerable. If the product is interchangeable, even changing the transmitter used will not affect the overall system.