Questions tagged [strain-gage]

A strain gauge measures the physical strain on an object. The most common types are a metallic foil attached to a flexible backing where the resistances changes when subjected to compression or tension.

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Obtaining Accurate Measurements from Strain Gauge

Background I have a strain gauge that I need to obtain measurements from. The product page indicates that the sensor is a half bridge configuration (one active/one compensating element). The sensor ...
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why is the reference of strain gauge changed depending on gains of amp? use ina128 and ad8542

I made a circuit for a load cell. It is available but when it is applied to the strain gauge, it has a problem. Reference voltage : 1.65 V When I measured value of load cell, I can see the change ...
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Options for impact sensors?

I'm looking for a sensor to sense impact, let's say the sensor is placed behind a thick metal/wood casing, the impact depending on the amount of force could either deform the casing or only causes ...
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What is this component that comes with this strain gauge?

I just bought a set of foil strain gauges from RS Components: https://docs-apac.rs-online.com/webdocs/16d3/0900766b816d3523.pdf However, it's my first time working with strain gauges, and I noticed ...
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Should we use wheatstone bridges nowadays?

For measuring strain gauges, the Wheatstone bridge is the historical choice. In a quarter Wheatstone brigde (\$350 \Omega \$ typically (?)), with a high input impedance amplifier, and some bridge ...
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Operational Amplifier and Strain Gauge

My laboratory involves using a strain gauge and an instrumentation amplifier to amplify the signal from the strain gauge. The op amp schematic is shown below: Any assistance with the following ...
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AD7730 calibration failure

EDIT: The exact issue is this, the ADC has a gain register (set during internal FS calibration and again at System FS calibration) and an offset register set during system zero calibration. The ...
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285 views

How does full wheatstone bridge with strain gauges work?

I have gone through a number of tutorials on Wheatstone bridge and how to use it to sense load using strain gauges. I have also gone through the calculations where one of the resistors of the ...
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1answer
117 views

Why is my amplified strain gauge output so unstable?

I've attached a strain gauge to a bending arm of a robot, and it varies by about 1.5 ohms from 356 to 357.5 ohms. I place this in a Wheatstone bridge. The strain gauge is R3. R1, R2, and R4 are all ...
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Any problem with this strain gauge configuration to increase resolution?

I'm new to using strain gauges, but I've seen the typical 1, 2, and 4 strain gauge wheatstone bridge configurations. Using the diagram below, I'm referring to where R3 is a gauge, or R3 and R4, or all ...
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Low current strain gauge

I am trying to make a low power device (based of RSL10 bluetooth SoC) that would sample a strain gauge @1kHz and transmit the measurements. The current drawn by the running SoC is about 1.5mA, while ...
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Wire shield when using connector for strain gauge sensor

I have made strain gauge sensor with 1 strain gauge. Thet gauge is in "bottom" part of Wheatstone brigde (one strain gauge terminal is signal, second is connected to ground). I'm using Sommer CICADA ...
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How to estimate force caused by a strain in a material from a strain guage?

So, I am learning about how strain gauges work and I understand that through stretching or compressing resistance of the staring gauge can be changed which can be measured in resistance accurately ...
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104 views

When is one active and one dummy strain gauge preferred to two active strain gauges?

As far as I understand, one active and one dummy strain gauge arrangement can be used for temperature compensation. But even two active strain gauges can be used for temperature compensation, and in ...
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106 views

Read data from strain-gauge Labjack, Arduino

I am working on a project where we have to record breathing data. For that we ordered a LabJack U3-LV along a with an amplifier (datasheet) and a belt which is some kind of strain gauge I think. We ...
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203 views

Strain gauge amplifier - so much noise!

I'd like to use atmega328p to read force with strain gauge. I'm using one 1k strain gauge and 3x 1k ohms dummy resistors. My circuit looks like that: I'm using DAC to remove offset from bridge. As ...
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72 views

Remove bridge offset before ICF amplifier or at FB pin?

I'm making project where I would like to read from stain gauge sensor. It will use only one 1k ohm (or 350 ohm) strain gauge and 3 dummy resistors to complete bridge (1k or 348 ohm). I'd lik to feed ...
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234 views

Wheatstone Bridge - strain gauge sensor

I'm trying to optimize a Wheatstone bridge with a strain gauge sensor and I'm considering all possible wire resistances. The circuit is shown in the following figure: I don't understand the comment ...
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1answer
349 views

What adhesive is best to glue strain gauges to metal?

I'm trying to use these strain gauges to measure bending of a metallic cantilever (metal TBD). Does anyone know what adhesive I can use to glue the strain gauges? I'd rather not have to use an oven ...
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97 views

in-amp for strain gauge

I'm working on a project where I should send an overload signal if the strain is bigger than 40 ppm. So far I found this answer: Strategy to balance a Wheatstone bridge for strain measurement The ...
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1answer
2k views

How does temperature compensation work for strain gauge in wheatstone bridge

Wheatstone bridge is used for temperature compensation for strain gauges If 2 strain gauges are connected like this figure. Due to temperature variation; the resistance Rg will change in the same way....
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274 views

What's the difference between consumer and industrial grade strain gauge adhesive? [closed]

Can I just use normal super glue and epoxy resin to attach a strain gauge?? What am I sacrificing by doing so? Also, how are load cells so cheap and what kind of adhesive / covering do they use?
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How much power does a strain gauge use?

Is it essentially nothing given how small they are? I see most configurations are given 5V, but does that mean they draw amperage as well?
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How to reduce noise in strain gauge measurements

I have two strain gauges on a 1 m length wind turbine blade which will rotate at 800 RPM. The amplifier and DAQ system will rotate with the blades. I'll have relatively noise environment and the ...
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1answer
81 views

Error in the gain, Amplifier, DAQ system

I have a strain gauge with maximum output of 5mV. I want to amplify this signal 1000 times in order to use my DAQ system to read it (the analog input range is 0-5V for DAQ connector). I have ...
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1answer
354 views

Compensating for offset voltage in bridge measurement before instrumentation amplifier

I'm using an instrumentation amplifier (INA118) to measure the signal from a full bridge strain gauge (tension only, all 4 resistive elements are strain gauges, slow changing (DC) signal). I'm using a ...
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1answer
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LM324 op-amp wheatstone bridge amplifier formula

I'm planning to use an LM324 opamp as a signal amplifier for a cell load (strain gauge in a Wheatstone bridge). This particular application is shown in the datasheet (see image). It shows the ...
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1answer
248 views

TrackPoint a.k.a pointing stick 2-axis force sensor

I have an application that would benefit from a sensitive two-axis force or bending torque measurement very much like what a pointing stick (a.k.a. TrackPoint) used to do in a ThinkPad, apparently ...
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3answers
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How do I use this Strain Gauge sensor?

The load cells here: http://www.cnloadcell.com/mlc700-postal-scale-load-cell and here: http://www.cnloadcell.com/mlc714n-personal-scale-weight-sensor have 4 wires (red, white, black, green). The ...
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2answers
2k views

how to connect strain gauge to HX711 module

I need get strain gauge reading to Arduino. so far i have found load cell Wheatstone configuration circuit here 3rd answer. I need to know if i connect a strain gauge to one +Active resistance, and ...
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1answer
174 views

ACAM PS09: Strain Gauge Stress Analysis

I've been working on implementing strain gauge measurements at my company for some stress analysis. There's a chip that I think works the best for our application. It's the PS09 by ACAM. However, ...
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4answers
2k views

Strategy to balance a Wheatstone bridge for strain measurement

The purpose of my project is to build a sufficiently accurate "Strain indicator" based on the use of a Wheatstone bridge using an Arduino. Currently I am using a HX711 as load cell amplifier which is ...
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1answer
76 views

Force sensor on uneven shape

I'd like to measure the force that a human leg impacts on a knee brace during normal gait. I have a problem in finding a suitable sensor for the job... The leg (and hence the brace) are not flat at ...
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3answers
1k views

4 Wire Strain Gauge to 2 Wire Conversion/Connection

I have the WK-06-12BT-350 ohm WK125BT Strain gauge from Vishay the Gauge comes equipped with 4 wires ( High endurance lead wires). The following document describes a similar gauge: Strain Gauge is it ...
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424 views

Load cell circuit does not work on circuit simulator

I want to simulate a load cell interfacing with AD620 for amplification. - My load cell is 40 Kg max with 2mV/V sensitivity and 10 V excitation voltage with input resistance of 405 ohm and output ...
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3answers
1k views

A question about choosing, implementing and placing a strain-gauge amplifier

This will be a little long question. Since I was and still am alien to some concepts, I will go step by step. Basically it is about implementing a strain-gauge amplifier and wiring configurations for ...
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1answer
71 views

A question about amplifying low level strain gauge voltages

I'm having difficulty in deciding about implementing an amplifier and whether I need it at all for a strain gauge. I never dealt with such situation before and would be very glad to have your opinions....
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1answer
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INA125P Strain gauge amplification problem

I'm using the INA125P to amplify the strain of a 350 ohm strain gauge in a self-built Wheatstone bridge circuit for measurement. I'm testing using a 351 ohm resistor to mimick a strain gauge under ...
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5answers
555 views

Measuring weight on a gym machine [closed]

We're doing a school project where we have to measure weight on a fitness machine. The user can select how many weight plates to use by moving a rod like shown in the picture. How would you do it? ...
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1answer
111 views

Voltage jump in time series data acquisition

This might be a basic question, but I am a Mechanical Engineer and hence stumped. I am acquiring (output) time series data from Strain gauge (excited by amplifiers). Attached plot is the output (ADC ...
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2answers
402 views

Copper Strain Guage

My understanding is that strain gauges are constructed using Constantan etched onto a flex PCB. According to wikipedia Constantan is highly suitable strain gauge material due to its high gauge factor. ...
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1answer
133 views

Negative differential to instrumentation amplifier causing problems

I am using a pair of strain gauges to make a weight scale. The strain gauges are the three-wire type that you can by on Amazon or Sparkfun. The strain gauges form a full wheatstone bridge, whose ...
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1answer
571 views

Strain Gauge - Wheatstone bridge DRIFT

I have a 350 ohm bridge with 04 fixed resistors, later on one of them will be replaced by a strain gauge sensor. In the meantime I am trying to understand where the drift is coming from. This bridge ...
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279 views

Measuring the angle of finger joints

I'm working on a project where I want to very accurately (+/- 1 degree) determine the angle at which a finger is bent. One of my main constraints is that my sensing mechanism can't interfere (much) ...
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3answers
306 views

Strain Gages Measurment Error and Saturation

I have an experiment composed of 16 strain gages, mounted on a steal beam. The steal beam is horizontally placed under a compression cylinder for a stress test. the test took around two hours to ...
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3answers
1k views

Wheatstone bridge offset

I have a Wheatstone bridge but I don't know the values of the resistances in it. My excitation voltage is 5 V. But instead of having 2.5 V on each output lines I get one line at 3.3 V and the other ...
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1answer
530 views

Measuring touch-weight resistance in piano keys

Piano technicians, such as myself, use an old, labor intensive way of measuring touchweight resistance in piano keys. I would like to automate this process electronically. This is an explanation of ...
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How many newtons could this BF350-3AA strain gauge support?

I am planning to purchase a strain gauge, the BF350-3AA in particular although there is no mention of how much force it is able to withstand. Also if someone could advise me of other strain gauges. ...
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317 views

Which one is the better way to feed analog input to my ADC?

I am planning to use an AD7730L analogue to digital converter (ADC) chip, with a quarter bridge circuit. Everything was on the track until I realised something, which indicated that things were ...
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2k views

Maximum sensitivity of a wheatstone bridge [closed]

Four strain gages are placed on an elastic element in order to measure axial force and moment. Assume that element cross-section is square with area, A = h2 . The strain gages all have the same ...