Few months ago I decide to bought an absolute pressure measure system using a Honeywell ASDX differential analog pressure sensor (Model: ASDX ACX 030PAAA5). The datasheet of this type of sensor attached.
Base on datasheet, this sensor has 3 active pin, pin No.1 is for voltage supply, Pin No. 2 is Analog output and Pin No. 3 is GND. The manufacturer suggest to use a load resistace > 5K ohms (I used a 4.7K RL) and an external bypass capacitor is required across the supply voltage (Pins 1 and 3). I used 0.1 uF and 0.001 uF capacitors between Vsupply, Vout and GND respectively.
I design a circuit on a breadboard to mount the sensor. I use a 5Vdc power supply device for the circuit, now when I TURN ON the device and there is no applied pressure on sensor (just ambient pressure), the output voltage is almost 2.47 - 2.59 Volt (I checked Pin 1 voltage for the sensor an itś same 5Vdc). the problems are here:
Problems: 1. I expect when there is no applied pressure, the output voltage be 2.5V but as i mentioned above it is a little less, what is the reason?
I will be so appreciate if help me.