Sensor

[chandu13]

hi

iam measuring the vacuum using vacuum sensor and displaying on the controller.

For 0v=10bar, 1v=20bar, 2v=30bar, . . . 9v=90bar, 10v=100bar

When I removed sensor from controller it is showing 10bar (0v) on the display.

How to do when I removed sensor from controller it should display “SENSOR OPEN”.

How to detect weather sensor is connected to the controller or not .

Regards
nari

 

[Leftyretro]

hi

iam measuring the vacuum using vacuum sensor and displaying on the controller.

For 0v=10bar, 1v=20bar, 2v=30bar, . . . 9v=90bar, 10v=100bar

When I removed sensor from controller it is showing 10bar (0v) on the display.

How to do when I removed sensor from controller it should display “SENSOR OPEN”.

How to detect weather sensor is connected to the controller or not .

Regards
nari

Assuming you are using an analog input to the controller and that 0 volts is a valid in range value, then a typical way to detect a 'loss of sensor' is to bias the input with a very high resistance to a 'top of scale' voltage, so called 'upscale burnout' and have the software logic detect this higher then full scale value as an invalid measurement. That means you will have to define in your software what the highest valid value will be and bias the input to something higher then that but still within the A/D measurement span. You will have to research the impedeance of the microcontroller's input and the sensor's output impedenace to determine the bias resistor's value.

Lefty

 

[Hero999]

For 0v=10bar, 1v=20bar, 2v=30bar, . . . 9v=90bar, 10v=100bar

Where did you get those figures from?

Did you pluck them out of thin air or are they from a datasheet?

I don't see how you can measure a vacuum as high as 100bar (unless you're 1km under water) because the pressure on the earth's surface if only 1bar.

You don't normally measure the quality of a vacuum in bar, you normally use pascals, torr or millibars.

 

[aswathnarayana]

sorry i am a newbie to this forum how to post a question in this thread

 

[Hero999]

Welcome to the forum.

I take it you want to create a new thread rather than just adding a reply to an existing one.

Click on at the top of the appropriate forum.