selecting sensor

Discussion in 'General Electronics Chat' started by sagacious, Feb 5, 2012.

  1. sagacious

    Thread Starter New Member

    Jan 15, 2012
    h3y guys im a biggn3r! n33d sugg3stins from you people..suppose we r given a task we3 n33d to s3l3ct s3nsor d3fin3t3ly w3 vl go through its characteristics but how? for example iam given a tsk that there a is a boiler temperature control..the temp: should be controlled at 800 degree centigrate.I know we will need a temp: sensor among those what should i choose & how? plus how can I defend my design? thanks
  2. PaulEE


    Dec 23, 2011
    I have a suggestion...TYPE LETTERS.

    I have another suggestion...look up "thermocouple". Used at high temperatures, thermocouples take advantage of the fact that a potential difference appears between two different metals at a temperature above absolute zero.

    They are often used in high temperature environments.

    For the question you're going to ask after you read this post, go to and look at instrumentation amplifiers. Their datasheets give examples of thermocouple schematics.

    After you build the circuit and it doesn't work right, re-design your circuit to take into account real-world op-amp non-idealities, temperature variation, as well as other thermoelectric effects between dissimilar metals in your physical circuit. Also, consider an offset potentiometer for null adjustments on the op-amp. Did I mention to design the circuit by keeping temperature changes in mind? That implies op-amp drift, resistor drift, correctly coupled and quiet DC power supply/ies, and careful physical and electrical circuit layout.

    By the way, account for temperature variation and thermoelectric effects. I think I said that already.

  3. sagacious

    Thread Starter New Member

    Jan 15, 2012
    thanks for the advices..i will try to put habit of writing posts in letters & will go through the academic suggestions too!
    Last edited: Feb 6, 2012