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I wish to buy this AD620 amplifier module for amplifying my strain gauge voltage. I also wish to use it with my thermocouple. Basically, I want to accurately read DC voltage values from around 0.1 mV to 40mV using my multimeter.

It says that the amplification can be up to 1000 times. I have the following questions for this module:

  1. Can it be used for DC voltage amplification?
  2. What is the maximum and minimum input voltage in millivolts that can be amplified?
JRE
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Atharva
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  • https://www.analog.com/media/en/technical-documentation/data-sheets/ad620.pdf RG=49.4 kOhm/(G-1). – Antonio51 Jul 14 '22 at 07:35
  • https://electronics.stackexchange.com/questions/625250/instrumentation-amp-giving-only-positive-output-with-and-power-supplies/625256#625256 AD620 Gain range =1 .. 10000 – Antonio51 Jul 14 '22 at 07:41
  • @Antonio51 what are G and RG in your first comment? – Atharva Jul 14 '22 at 07:44
  • G is the Gain wanted with AD620 (see datasheet page 12 ... and RG is the value of resistor between the two dedicated inputs (pins 1 and 8) of AD620. Now, you should search what is the schematic of your board if you don't know the use of the two potentiometers on the board. Ok. Use of these pots is included in the web page. – Antonio51 Jul 14 '22 at 07:49
  • It seems something of this http://vctec.co.kr/product/ad620-acdc-%EC%A0%84%EC%95%95-%EC%8B%A0%ED%98%B8-%EC%A6%9D%ED%8F%AD-%EC%95%B0%ED%94%84-%EB%AA%A8%EB%93%88-ad620-high-accuracy-instrumentation-amplifie/18195/ https://protosupplies.com/wp-content/uploads/2021/02/AD620-Instrumentation-Amplifier-Module-Connections.jpg – Antonio51 Jul 14 '22 at 07:56
  • Don't use it with your thermocouple, see your other question for why. Use it with your strain gauge, but you need to take other precautions with your gauge supply voltage and ADC reference to maintain accuracy, see your other question for why. – Neil_UK Jul 14 '22 at 08:10

1 Answers1

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Well, the Description tab answers all of your questions.

Can it be used for DC voltage amplifications?

From the product description:

Can be used for AC, DC signal amplification.

What is the maximum and minimum input voltage in millivolts that can be amplified?

Again, from the product description:

  1. The AD620 amplification can amplify microvolt, millivolt, offers higher amplification precision than LM358, the max voltage output range is ± 10V.
  1. It uses a potentiometer to amplify the input signal, max amplification can be 1000 times, can be adjusted by the potentiometer.

The maximum output is ±10 V, the amplification range is 1.5 ~ 1000. If you set the amplification to maximum then the maximum input can be 10 mV.

But note that you should still measure the amplification factor by hand first.

Rohat Kılıç
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  • Is there any limit on the input voltage that can be amplified accurately? Also, to measure till 50mV I can set the amplification factor to 200 right? – Atharva Jul 14 '22 at 06:56
  • There's no information given but the description says that the module can be used for amplifying microvolts accurately. This is the product's claim, not mine. – Rohat Kılıç Jul 14 '22 at 06:57
  • How do I "first measure the amplification by hand"? I do not have a millivolt generator. – Atharva Jul 14 '22 at 08:47