FAQ
Click on the arrow next to the questions to expand/collapse the answers.
Technology
Conventional load cells are built using strain gauges or piezo resistive devices which are basically variable resistors arranged in a wheatstone bridge network. When a strain/stress is applied to the strain gauge – it changes the resistance of one or more resistors slightly. This change in resistance leads to an unbalanced circuit resulting in a small milliVolt change in output signal that is amplified and calibrated to measure loads. Typical full scale outputs are in the 20-40 mV range.
In comparison, our load cells are built using variable capacitors. When a load is applied, the capacitance changes significantly and is converted into a digital frequency signal. As the load changes, the frequency changes. This frequency change can be measured very accurately and can be converted into either a digital (USB, Bluetooth, XBee Wireless, WiFi) or analog(0-5V, 0-20 mV, 4-20 mA) signal that is easy to input DIRECTLY into a DAQ or a PLC or a PC.
Maximum Input Voltage = 5V Input Voltage Noise < 100µVrms Input Current = 50mA max
We offer some NTEP certified resistive load cells in some configurations and capacities such as the RRP1 and RRP2 Single Point Load Cells and the RRS1 S-Beam load cells. The RSP1 Single Point Load Cells are OIML approved. These resistive load cells are sourced from reputable third parties who have been building resistive load cells for a long time.
Generally speaking iLoad series load cells are designed to be used in a static loading situation. The load cells perform well in a dynamic environment as well but are limited to approximately 3 to 5 millisecond response times.
If you are looking for faster response rates you can utilize one of our resistive analog load cells in combination with our DI-1000UHS-1K digital USB interface with data output rate of 1 khz to capture faster dynamic forces with our LoadVUE Pro, SensorVUE or ControlVUE software.
As far as true impact force measurements are concerned, we offer a complete solution with a resistive force sensor, a DI-1000UHS-10K USB interface with up to 50 khz data rates and LV-1000HS-10K software to capture, display and plot data on a Windows PC or Tablet. Please review our Impact Force Measurement page for further information.
Yes, 3D models of many of our load cells are available under the Support Menu option on site. You must register and login before you can access and download these files. If you do not find what you need, please contact us.
You can use any of our iLoad Series load cells with the optional 0-5V analog output. You can also use any of our resistive load cells with the AI-1000 Single Channel Load Cell Signal Conditioner which provides a 0-5V output that can be input directly into most DAQs or PLCs. We also offer a 4-20 mA output via the AI-1000-CV analog signal interface.
Yes we provide calibration data that shows the applied load vs. measured loads using our load cells. For analog load cells, we supply a calibration curve that shows load vs. voltage.
The iLoad Analog series load cells have a linear output with approximately 0.5V at zero load and approximately 4.5V at full load.
The S2U adapter converts Serial TTL (UART) signal from the following devices to USB signal; the USB still appears as a virtual COM port to Windows/Linux/Mac applications. Please visit this page for the latest drivers.
- DI-100U
- DI-400U internally uses 4 S2U adapters.
- DQ-1000U
- DQ-4000U
- DS-4000U
- iLoad, iLoad TR and iLoad Pro series load cells.
- The DI-1000U does not need this adapter.
- When the load cell or the digital USB load cell interface is connected to the computer, does an USB port show up in the device manager?
- If the answer is No, then the drivers may not have been properly installed. Please download and install the drivers from this page.
- Some devices and load cells need an S2U adapter (dongle) to convert the signal from the device into USB. See the answer to the previous question. Make sure you are using this adapter from Loadstar Sensors. You cannot use a off-the-shelf standard USB-A-male to mini-B-male cable with these devices. Our S2U adapter contains proprietary electronics to perform the serial to USB conversion.
- The DI-1000U does not need this adapter. So an off-the-shelf cable can be used with DI-1000U. Do not use the S2U adapter with the DI-1000U.
- If the COM port shows up on the device manager, but the software still does not recognize the device then check the cable connections to make sure they are tight. If necessary, try replacing the cable.
- If the problem is with the DI-100, is the led on the DI-100U blinking? If yes, the dongle and the cable are providing power to the unit. If not try replacing the dongle or the cable or both.
- Some DI-1000U units have an on-off switch. Is it on?
iLoad Digital USB Load Cells
Yes, but only for the iLoad, iLoad TR and iLoad Pro Digital USB load cells – not the iLoad Analog load cells. You would need to provide a 5V regulated power supply to the iLoad Analog load cell. Any offset from this voltage will cause a similar offset in the output voltage.
iLoad Mini USB Load Cells
The iLoad Mini load cells has 2 frequency outputs. When Control Input = logic ‘1’, the Mini outputs the load cell frequency, Fsensor. When Control Input = logic ‘0’, the Mini outputs the reference frequency, Fref. The compensated frequency Fcomp = Fsensor - K*Fref, where K is a constant provided by Loadstar. Loadstar can provide the coefficients for the quadratic equation to translate Fcomp to weight. Although possible in theory, most customers do not have the equipment, skill or time to perform calibration in their facility, hence we recommend that you purchase the Mini Load Cells with the DQ-1000 or DQ-4000 interface devices.
This can be tested by launching the Hyperterminal application from Windows XP, opening up the relevant COM port and sending the command "O0W1". The load cell will return the sensed load in millipounds as an ASCII string. LabVIEW or Matlab can retrieve this string and process the result. See Driver Installation and Hyperterminal Operation for more information and examples using LabVIEW and Matlab.
iLoad Analog Load Cells
You can use a 9V battery with a regulator to regulate down to 5V from 9V. You just have to be careful that the battery doesn't deplete down to below 5 V since the output signal will then start dropping with the drop in voltage.
Interfaces
The biggest difference between both interfaces is resolution and accuracy. The DI-100 has a 16 bit ADC while the DI-1000 has a 24 bit ADC for much greater resolution. Additionally, the DI-100 has an accuracy of ±0.1% and the DI-1000 is accurate to ±0.02%.
Software
Yes, we provide drivers for several different platforms including Windows (8, 10, and 11), Mac OS and Linux. Since we use the industry standard FTDI chips to convert serial output from our load cells and interfaces to USB output, any platform that supports these FTDI chips will be able to read our devices. Please visit http://www.ftdichip.com/Drivers/VCP.htm for the latest drivers for your platform.
Once the drivers are installed, the device appears as a virtual COM port to the system (similar to a Bluetooth device). The device then can be read with any terminal or modem program that can read serial ports.
Note: iLoad series load cells purchased prior to March 2009 will only work with 32 bit versions of Windows XP. If you have these load cells starting with serial no. F09xxxxxxxx then, you must contact us to purchase replacement load cells.
Building Wired and Wireless Scales
You can connect at least 3 but typically 4 (for improved mechanical stability) iLoad Digital USB load cells to your PC either directly if it has 4 USB ports available or via a USB Hub that has 4 ports with a single UBS connection to the PC. Install and run LoadVUE Pro 4000 software. LoadVUE can display individual as well as the summed total of the weights or loads on the four load cells.
Discounts and Warranty
We have a 90 day warranty policy.