Load Cell

Thank you for visiting the ATO online store. Here, we are dedicated to offering valuable information regarding load cells, force sensors, load cell transmitters, and amplifiers. We aim to provide you with FAQs, troubleshooting, wiring guides, and calibration methods to enhance your understanding and usage of these essential components.

In the section below, you'll find answers to some of the most frequently asked questions (FAQs) we receive about load cell and force sensors. Before seeking direct assistance, we encourage you to review these answers, as they may contain the information you're looking for. However, if you still have questions or require further assistance, please don't hesitate to reach out to our ATO engineer service team. We're here to help.

Load Cell FAQs and Troubleshooting

1. 0-500kg Load Cell Reading

Q: I am trying to troubleshoot a problem that I am having. I have repeated the same test 5 times, changing nothing, yet getting 5 different load cell readings.

To get into the details: I have a DYMH-103 0-500kg load cell that I purchased last fall. I have it connected to a DTS SliceStack and use DTS Sliceware to record the data. I also collect data from a DTS 6DXPro (6 degrees of freedom gyroscope and accelerometer). The excitation voltage from the DTS system is DC 5V, I know on the certificate for the load cell it says 10V, but the user documentation on the website says 5-15V.

I do impact testing for football collisions. I have a pendulum with a 15.3 kg mass, on which the load cell is mounted. I impact a head form that has the 6DXPro mounted inside. I record 4 seconds of data from the load cell, 3 accelerometer channels, and 3 gyroscope channels.

For each of the 5 tests I performed the linear acceleration and angular velocity profiles were consistent, the load cell readings however changed drastically. They increased with each test from 29kg to 49kg to 108kg to 120kg then drastically dropped to 10 kg on my last test.

A: The structure of the model DYMH-103 you purchased is unsuitable for impact testing. When installed horizontally, the weight of the sensor itself will also have a certain impact on the measurement. Therefore, the output measurement value will be unstable and inaccurate under these factors. For your testing, it is recommended that you use our MH-105. Please install it vertically, and use the vertical direction for impact testing.

2. ATO-LC-TC01 Load Cell Troubleshooting

Q: I have an ATO-LC-TC01 load cell, which I think is malfunctioning and needs support with it. The problem is as follows:

When I measure the bridge impedances with a multimeter, I only get 350 ohms on the Red/White and Green/Black pairings; all other measurements are Open Loops. The top cover of the unit is loose and can fall off of the threads, exposing the internals of the load cell. When connected to the ATO-LCTR-DY510 load cell amplifier, the output from the amplifier is -13V, which I believe indicates that the amplifier is not seeing a proper connection to the load cell.

This all occurs whether the load cell is in tension, compression, or no load. Is there any further troubleshooting I can do with this unit? Is there a recommended installation procedure for these load cells to ensure they are not damaged by the tightening process on the threads? This is an urgent problem for a line of machinery that is being built currently.

A: If the red/white and green/black pairings are only 350 ohms when the multimeter measures the bridge impedance, and all other measurements are open-loop, it means that the sensor is damaged inside. When installing the load cell, do not screw the screw to the end, and the screw should not touch the ring surface of the sensor, otherwise, the sensor may be damaged.

3. 50kg Tension/Compression Load Cell

Q: I’m trying to decide on a 50kg tension/compression load cell for my project and just have a few questions that I can’t seem to get an answer to.

1. For this product which I will call the cylindrical load cell, the weight is shown as being 100g. From my calculations, it couldn’t be over 70g even if it were solid stainless steel. Does the 100g mass include the cable? If not, what is the total mass of the sensor and the cable?
2. Also, just to confirm, I understand this is a strain gauge-based load cell. Is there a datasheet that shows the configuration or information about the bridge that’s chosen? I have some concerns about the signal creep.
3. The other load cell I am currently considering is this product (ATO-LC-S03). Any additional information that could help me decide between these is appreciated. The mass of the load cell, the linearity of the signal, and the signal creep are the most important features.

A:

1. The weight of different measuring ranges of the sensor is different, and the weight includes the weight of the cable.
2. Sorry, we don't have the configuration or information about the bridge that's chosen.
3. For the quality, signal linearity, and signal creep of the DYLY-106 load cell, please refer to the specification table.

4. Connecting 50kg and 300kg Load Cells to a Computer

Q: I am working on a research station in Norway and we have 12 load cells (50kg and 300kg) that we want to connect to a computer so that we can follow the weight over time. Is that possible, and what do you recommend?

A: We can recommend using ATO multi-channel junction box to connect the load cell to get one output and then connecting the junction box output signal to our Digital Load Cell Amplifier, to output the RS485 signal, and then connect to the computer software through the 485 signal to monitor the weight information.

5. Load Cell: Tension and Compression

Q: Will your compression and tension load cell like SKU: ATO-LC-P02 work for both tension and compression for the same application/installation? If yes, then what will be the difference if it is subjected to tension and then to compression for the same application/installation?

A: Yes, this low profile tension/compression load cell can work for both tension and compression in the same application/installation. Its output signal has positive and negative points (maybe the tension is +, and the compression is -), if you switch the SIGN+/SING- wiring of the weighing sensor, you can switch this ±. So when the sensor outputs 0V, it corresponds to zero load, and when it outputs ± 20mV, it corresponds to full tension or compression.

6. Load Cell Reads Dynamic Force

Q: Can you load cell read dynamic forces? In other words, can I apply a thrust of 4 seconds on it and have it accurately read out the acceleration and deceleration of the thrust?

A: Yes, our load cell can read dynamic forces. The response frequency of the sensor is about 300Hz, which requires the sampling frequency of the display controller connected to the sensor to be fast enough, so it can read the changes of thrust addition and subtraction.

7. Load Cell for Plastic Extrusion System Safety

Q: We have a small plastic extrusion system where the melted plastic strand may "fall" out of the die and onto the floor and continue to form a pile.  This is a system that does not have constant monitoring so we would like to put some type of load cell on the floor where it would sense a load and then sound an alarm and flash a warning light so the stand can be put back into the processing line.

A: We also need to know what is the approximate weight (kg) of the melted plastic falling onto the floor. If it is too light, the load cell may not be able to detect it, so we need to know what is the approximate weight range of the plastic.

8. Button Load Cell Installation and Wiring

Q: I received two of your button load cells (SKU: ATO-LC-BU02) and had two concerns I wanted to address.

1. The first is that the bottom of the load cell has an "outer" and "inner" surface and I am unsure how to properly mount the button sensor with regards to these rings. Should the support touch the "outer" ring, "inner" surface, or both?
2. My second concern is with the ends of the sensors. One sensor has all 4 wires and a shielding wire. The other has no shielding wire and seems to be taped up.

A:

1. The force-bearing surface is the raised part in the center of the sensor, not the annular surface.
2. The lack of shielded wire will have no effect. You can leave the shielded wire unconnected, and the sensor can be used normally.

Load Cell Transmitter (Amplifier)

1. Couple a Digital Load Cell Amplifier with a Torque Sensor

Q: We would like to couple a digital load cell amplifier (SKU: ATO-LCTR-OAR) with a torque sensor, and are currently trying to test the amplifier response by putting a voltage in the range of 0-20 mV across the signal (SIG), while also supplying it with 12V on both the inlet (EXE) and outlet (P) sides of the amplifier to power it.  When applying the signal voltage, we do not observe any response in the amplifier display, which simply reads "0" or sometimes "-8". We have checked with a voltmeter that the voltage is reaching the amplifier. Are we going about this the right way?

A: This transmitter ATO-LCTR-OAR can be coupled with an ATO torque sensor, please refer to our suggestions on how to test:

1. First, make sure that the torque sensor and transmitter are wired correctly, you can refer to the user manual of the transmitter or the video below. 
2. After completing the wiring, start the test: in the no-load state, measure the green and white lines of the output signal to check what the output voltage is. Then apply a certain torque, and then measure the output voltage of the green and white lines again, and check whether there is a numerical change in the output voltage.

Note: If the output voltage is -8, this means that the torque you are applying is reverse torque. You can change the positive and negative display of the output signal by swapping the green/white wire (the input signal wire of the load cell).

Related blog: How to Calibrate Digital Load Cell Amplifier?

2. Calibration and Range Setting for Load Cell Transmitter & Torque Sensor

Q: I bought your high-precision weight transmitter and reaction torque sensor.

1. The goal was to read the values from 0-5V, however, it seems that the actual output is around 4.9V to 5.2V, is this due to an incorrectly assigned CF value?
2. In the documentation, you state that the “total load range 1/10 to remain stable”. If I have a 20Nm torque transducer, I can not exceed the 2Nm of torque, correct?

A: When you calibrate the torque sensor and the transmitter, you should set the range of the sensor to be consistent with the total range of the transmitter (for example, if the torque range is 100NM, the transmitter should also be set to 100), and the transmission output signal 5V should be set to correspond to the CF value during calibration.
The manual mentioned that the calibration weight is 1/10 of the total range of the load cell, which means that if your load cell range is 100 kg, then the calibration weight you use is at least 10 kg. Of course, if your calibration weight is bigger, and closer to the sensor's range of 100Kg, the calibration will be more accurate. In the same way, if your torque sensor is 20NM, you can apply a calibrated torque of at least 2Nm, that is, not less than 2Nm for calibration. It would be better if you could apply a calibrated torque of 5Nm, or 10Nm.

3. Load cell Amplifier and S Type Load cell Calibration

Q: We have purchased the ATO-LCTR-OAR Load cell Amplifier and ATO-LC-S01*(10Kn) S Type Load cell, but unable to get a good calibration.
I connected the load cell and powered transmitter, set Parameter 01 SL (zero point) at 00000, set Parameter 02 SH (load calibration value) at 107.23. I placed 107.23 Kilograms of calibration weight on S type load cell, set Parameter 04 SD (decimal place) at 2. Removed calibration weight and exited programming. When I place the calibration weight on the load cell the display now shows me 466.14 instead of 107.23. What am I missing in programming?

A: Since your load cell range is 10Kn=1000kg, you need to set Parameter 04 SD (decimal place) at 1, it can only be set to 1 decimal point. You could re-calibrate, and test again.

4. Signal Conditioner for Load Cell

Q: I’m searching for a signal conditioner for a load cell to reduce noise/other disturbances and improve accuracy on a weighing machine. The load cell has a 10 kg capacity, an excitation voltage of 10V, and an output of 0-20mv. I was looking at the ATO-LCTR-DY510 as a potential solution but I’m not sure if it will be compatible with the target machine. Currently, the load cell connects directly to the machine without an external amplifier and I was concerned that the 0-5V output of the transmitter will be too high.

A: The signal conditioner ATO-LCTR-DY510 of the load cell supports load cells with a capacity of 10kg, an excitation voltage of 10V, and an output of 0-20mv, and can output a signal of 0-5V. But we also want to confirm what are the specific factors of on-site interference. And what is the accuracy requirement of the output signal?

5. Recalibration When Changing Load Cell Capacity

Q: When using your load cell transmitter with 10kg load cell capacity, then I want to disconnect and use it for another load cell capacity, would I need to re-calibrate?

A: Yes, you need to re-calibrate the transmitter again, because the setting of the transmitter is related to the range of the load cell.

6. Torque Sensor & Load Cell Transmitter Troubleshooting

Q: I have an ATO-TQS-S04 torque sensor paired with ATO-LCTR-OA load cell rated for 20Nm and an output of 0 +- 10V, but I am having trouble using it. No matter how much torque I apply, the voltage output remains the same, even when I apply no torque to the load cell. Do you have troubleshooting ideas and/or a manual for both products?

A: You need to calibrate the torque sensor ATO-TQS-S04 and the transmitter ATO-LCTR-OA. The calibration method is similar to calibrating the load cell, you can refer to the manual of the transmitter, and a video-calibrated load cell for your reference below.
When calibrating, you need to apply a torque of 5Nm or 10Nm to the torque sensor as a calibration value, and it is similar to the weight (Kg) applied in the video.

Related blog: How to Calibrate Load Cell Transmitter?