I'm trying to device an instrument comprising two infrared proximity sensors that can be used to check for the straightness of slender (tall) concrete columns. The proximity sensors would be placed at the top and bottom of a 2 metre tall metal pole. The two sensors should work at the same time. Their output are to be compared by a different circuit. If their output are not the same, a buzzer keeps sounding until their output becomes the same. But my problem is that i don't know of any circuit or circuit diagram that can compare the output of there sensors. Please can anybody help me out. The diagram for the sensor is at http://www.electronic-circuits-diagr...simages/19.gif

 

someone please help me out.

 

hi,
Buy a low cost RED visible laser pointer, point it up the column.
Use a piece of white card or plastic to see the laser spot at the top of the column.

That will check for straightness, but not for vertical accuracy.

__________________
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/

 

But can a voltage comparator do the job. That's comparing two voltages for equality. If unequal the alarm remains on until they are equal by adjusting the form of the column.

 

The TX and RX modules shown in your link are 38KHz pulsed IR.

The output of the RX module is either High or Low depending upon the received IR pulses.

The IR beam from the TX unit has a beam width of about 5 to 10 degrees and the RX unit about 20 degrees.
This would make any accurate measurement for 'straightness' impossible.

I would use a cheap RED laser pointer at one end of the column and a collimated opto detector at the other end of the column.

When the laser pointer is being detected by the opto, an audible sound is generated whose intensity/frequency is proportional to the signal strength at the opto receiver.

__________________
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/