Greeting Everyone ,
I am doing a project of data acquisition system Let me explain project in simple terms Step 1) Sensor : A strain gauge type PRESSURE sensor (Wheatstone bridge)Specs : 2mV/V output I am applying +- 5Volts (10 Volts) The output swings from 0mV to 20mV(full pressure)
Step 2) Instrumentation amplifier : Output of the sensor is given to an instrumentation amplifier which i made using 3 OP07 opamps i have also added a filter at the end of amplifier to reduce noise.Specs : the circuit has two ZERO pots (to adjust Zero output)(Connected at zero net ) and an Gain adjustment pot .Gain adjustment pot is connected at R5
Step 3) ADC : The output from this circuit is gain adjusted (typically gain =100) and given to ADC ADS1115. ADS1115 has capability to take the differential input directly and also has provision for programmable gain Upto 128 Which looks something like this :
so i just interface my controller device with the above setup to get data (Data Acquisition ) and plot graphs etc
------Question------- Can we Totally bypass instrumentation amplifier and directly (maybe add a filter)connect the output of sensor to ADC ? 1) adc will do work of converting the differential signal into binary data 2) We can avoid the instrumentation amplifier circuitry 3)ADC has programmable gain which we can set to 100
Any suggestions and reviews are welcome ! Thank you in advance !!