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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33 views

Common voltage of 2 op amps instrumentation amplifier

I am trying to build an amplifier for a strain gauge sensor using the 2 op amps instrumentation amplifier design provided in the Texas Instruments note: https://www.ti.com/lit/an/sboa247/sboa247.pdf?...
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Strain gauge measurements with carrier frequency

In near future, I would need to do strain gauge measurements using HBMs instruments, the amplifier will be MX1615B. In my case, the gauges will be placed near a 50Hz gearmotor and run with VFD. As far ...
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230 views

Strain gauge in a voltage divider

I have a strain gauge mounted in a voltage divider as in the image below: simulate this circuit – Schematic created using CircuitLab where \$R_{g}\$ is the resistance of the strain gauge when ...
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29 views

Reduce load cell creep and drift programatically

I am trying to build a weigh scale and have read through the parameters that affect its reading in the long run. My question is can we reduce the Creep and drift of the load cell by compensation ...
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71 views

Why are two pairs of a wheatstone bridge of opposite direction?

I wonder why are, e.g. when using a wheatstone bridge in combination with strain gauges, two of these SGs do have a positive k-factor and the other two a negative k-factor. Gladly, there is already ...
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77 views

4-Wire Strain Gauge Measurement

I want to accurately measure the resistance of a single strain gauge, unaffected by lead wire resistance and with ratiometric ADC conversion to compensate for excitation drifts. I know for RTD ...
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133 views

How to connect two load cells to one HX711?

I have two 5 kg load cells and one HX711. The project's goal is to connect them together, and measure the weight of the same object. I would like to get the average in order to make my calculations ...
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26 views

Evaluation of multiple Wheatstone bridges using one instrumentation amplifier

I need to measure 8 different strain gauges. I am thinking about using just one instrumentation amplifier to evaluate all Wheatstone bridges (because of the high price of instrumentation amplifiers.) ...
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1answer
47 views

Load cell behaving weirdly. Output magnitude of force depends on which side is held and which side force is applied

also asked at: https://forum.arduino.cc/index.php?topic=670246.0 I have a generic load cell (image) and am using Hx711 which is connected to arduino. The code is from Instructables. When I fix and ...
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115 views

Loadcell strain gauge with 10 V excitation

I am designing loadcell (spec) measuring using 24-bit adc (MCP3561) with excitation 10 V. But I couldn't find the reference design for 6-wire loadcell that its sense pins connect to ref+ pin of ADC. ...
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117 views

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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27 views

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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41 views

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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1k views

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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1answer
116 views

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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176 views

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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2answers
414 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
188 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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29 views

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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2answers
87 views

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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54 views

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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1answer
34 views

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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1answer
212 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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1answer
138 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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1answer
259 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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90 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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443 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
483 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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1answer
115 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
3k 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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2answers
437 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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2k views

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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613 views

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
84 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
623 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
5k views

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
316 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
1k views

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
211 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
80 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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0answers
538 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
2k 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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72 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
1k views

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
606 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
115 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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482 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. ...