FAQs

Do I need an Instron device to calibrate my ELF system?

Question: Do I need an Instron device to calibrate my ELF or WELF?

Answer: No! You can use dead weights and that will work fine. The video calibration tutorial uses one, but it's not necessary.

 

Link to this FAQ

How is the F-Scan64 system different from the F-Scan System?

The main difference between the F-Scan64 and F-Scan systems lies in the micro-sized electronics.  The F-Scan64 electronics allows for a completely cord-free Bluetooth connection system with a quick setup time of three minutes or less. Also, users do not need to trim sensors.  The number “64” refers to the number of sensing elements in the sensor regardless of the sensor size.  

The F-Scan GO system offers trimmable sensors with up to 966 sensing elements (at full size) and can scan at rates up to 500 Hz. The F-Scan GO systems uses advanced gait analysis software for more detailed analysis.  

Link to this FAQ

How to improve calibration accuracy and repeatability with ELF?

Issue: After calibration with a known load (via the INSTRON) we get errors of approximately +/-20%. We used different sensors but the error remains the same.

Solution: Make sure the sensitivity is set correctly. (The maximum load should be about 80%-90% of the full range.) Check this before the sensor is calibrated by applying the maximum load and making sure the number that is output (% Digital Output) is between 80-90% on the screen. Since the system uses an 8-bit analog-to-digital converter, this would translate to a “Raw” digital output value of about 200-230 out of a maximum of 255 (8-bit).

In the calibration screenshot below, the "Raw" value is 34 (out of 255) for the highest calibration point.

Calibration menu screeshotCalibration menu screeshot

This point, 34 (out of 255) is at the very beginning of the Sensor's curve, which is not very predictable. Since the repeatability error is based on the full-scale value of 255 Raw, you will want to increase the Sensitivity until the load you are measuring will use 80%-90% of the full range.

Link to this FAQ