Selection of pressure transmitters

Thread Content

1. Pressure transmitters can be divided into three categories based on their operating environment: first, intrinsically safe type; second, flameproof type; third, ordinary type. Both intrinsically safe and flameproof types have explosion protection capabilities; however, due to their different explosion protection ratings, their areas of application also differ. Next, let’s take a look at the first type of intrinsically safe device: Intrinsically safe transmitters utilize intrinsically safe circuits and are generally used for measuring flammable and explosive substances. They have strict requirements regarding external power supplies – the current must not exceed 165 mA, the voltage must not exceed 30 V DC, the power consumption must not exceed 0.9 W, the parallel capacitance must not exceed 0.02 uF, and the parallel inductance must not exceed 0.73 mH. In such cases, a safety barrier is necessary to meet these requirements. II. Flameproof types also use intrinsically safe circuits, but they have excellent sealing properties; they are generally used in flammable and explosive environments, where it is only required that the external power supply voltage not exceed 30V. During installation, it is essential to follow the requirements regarding the shock protection level and the provided diagrams to avoid accidents. 2. The selection of the diaphragm box should be based on the chemical composition of the medium to be measured, the ambient temperature, and the measurement range. 3. Select the output signal, pipeline interface, electrical interface, display gauge, installation method, etc., as required.