Beginners choose sensors

When we do a project , After the flow chart of the system is designed , Sensor selection is required .

There are many manufacturers of online sensors , Will provide quality services . If this is the first time you choose a sensor , We need to design according to the requirements , Provide the manufacturer with the parameters of the sensor , Ask the manufacturer to help select models .

The main parameters that affect the sensor are as follows ：

1. range

Look at the range , Leave a margin . Select the measurement range ,

Such as pressure sensor , for fear of “ Water hammer effect ” The resulting impact damages the sensor , At least affordable 2 Multiple range .

Working range of hydraulic oil 30-80℃.

Pressure sensor 10bar=1MPa,1000psi=6.89MPa

2. Look at the interface （ How to connect ）

For stress （ Hydraulic pressure ） Sensor or flow sensor , Consider the installation method . Pressure sensors are usually connected by flanges , At this time, you need to know the diameter of the pipeline DN.

  Flow sensors include turbine flowmeter and electromagnetic flowmeter , Conductive electromagnetic flowmeter , Non conductive turbine flowmeter . For example, plug-in , Need to punch holes in the pipeline , Then apply threaded connection .

 

3. See output （ voltage / electric current ）

There are two kinds of sensor output , Voltage and current . The voltage output has 0~5VDC and 0~10VDC Two kinds of ; The current output has 4~20mA and 0~10mA Two kinds of .

 

Voltage output is convenient for field wiring , The current output has strong interference ability , Suitable for long distance transmission .

Voltage signal PLC Equivalent to voltmeter   Four wires and three wires are easy to connect Not easy to make mistakes

Current signal PLC For ammeter , The ammeter should be connected in series into the circuit It's easy to get wrong .

 

Sensor wiring for voltage output （ Three line ）

  Sensor wiring of current output （ The second line ）

4. See if there is a digital display , The sensor with digital display is convenient for on-site debugging .

5. Measuring medium , Conductive medium electricity - Magnetic flowmeter , Non conductive medium - Turbine flowmeter .

6. Power supply . commonly DC24V that will do .

7. Look at the accuracy , Generally speaking, there are 0.1%fs  0.25%fs  0.5%fs.fs（full scale） Full scale .