signal adjuster

Discussion in 'The Projects Forum' started by pprentis2, Apr 5, 2009.

  1. pprentis2

    Thread Starter New Member

    Apr 5, 2009
    I am trying to build a device to adjust the output of an air flow sensor. The sensor is calibrated for operation in a 2.75" OD tube and I need it to function correctly in a 3" OD tube. So the signal would be off by approximately 19% I believe. Voltage output varies linearly by 0-5 volts depending on air flow.

    Can I just use a basic op-amp circuit or would that not be accurate enough? It needs to be adjustable so I can fine tune it and my experiance with varriable resisters is that they are not very accurate.

    Any help would be appreciated.

  2. KL7AJ

    Senior Member

    Nov 4, 2008
    Garden variety potentiometers can be pretty sloppy, but precision multiturn pots are available....for a commensurate price.

    An alternative, if you don't need really fine resolution, is a series of switchable metal film resistors, accessed through a few DIP switches. (The phone company uses this method for setting levels, and it's very stable).