Go Direct^® Hand Dynamometer (GDX-HD)

Specifications and User Guide

Troubleshooting

General: Press the power button on the sensor to turn it on. Connect your sensor as described in the Getting Started instructions for your device.

• Primary Test: Confirm that the sensor was properly zeroed. If the sensor does not read zero in the orientation in which you are using it, follow the standard zeroing procedure for the data-collection program you are using.
• Secondary Test: Confirm that you are using Graphical Analysis app version 4.7 or newer.

Additional Troubleshooting

• Channel Numbers for GDX Sensors in Python and other coding languages
• Go Direct sensor does not connect to LabQuest 2 via Bluetooth.
• How many wirelessly connected Go Direct sensors can I use for data collection at the same time?
• Troubleshooting Bluetooth Connections with Go Direct Sensors
• What can I do if a Go Direct sensor's Bluetooth LED flashes red and green when I try to connect to it and the connection fails?
• Will my device work with Go Direct Sensors via Bluetooth?
• How do I know if my LabQuest will work with Go Direct Sensors and Go Wireless devices?

Specifications

• Range
  ⚬ Force: 0 to 600 N
  ⚬ Acceleration (3-axis): ±156.8 m/s² (±16 g)
  ⚬ Gyroscope (3 axis): ±34.9 rad/s (±2000°/s)
• Maximum force without damaging the sensor): 850 N
• Resolution: 0.1 N
• Maximum Sample Rate: 10 samples/s
• Connections:
  ⚬ Wireless: Bluetooth^® v4.2 (wireless range 30 m unobstructed)
  ⚬ Wired: USB 2.0 full speed
• Battery: 300 mA Li-Poly
  ⚬ Battery Life (single, full charge): ~24 hours continuous data collection
  ⚬ Battery Life (lifetime): 2 – 5 years (typical)

Calibration

Calibrate? No. The sensor is set to the stored calibration before shipping. No calibration process is given. However, you may consider “zeroing” the force sensor before the start of an experiment. If the sensor is not reading zero in the orientation in which you are using it, follow the procedure below:

1. Hold the Hand Dynamometer in the same orientation you plan to use it. Do not put any force on the pads of the Hand Dynamometer.
2. When the readings stabilize, click or tap the Force meter and choose Zero. The readings for the sensor should be close to zero.

Battery Troubleshooting

1. If the sensor can be turned on when connected by USB but not when disconnected from USB, the battery likely needs charging.
   ⚬ Charge the sensor for several hours and try again.
2. If the sensor shows fully charged but still won’t turn on when connected via USB, then the battery has likely disconnected.
   ⚬ Check the battery connection.
3. If the sensor still won’t turn on, try swapping the battery with a working sensor to see if the problem follows the battery or stays with the sensor.
   ⚬ If the problem stays with the sensor, the battery is probably not the issue.
   ⚬ If the problem follows the battery, the battery has likely reached its end of life.
4. If the battery is indeed at the end of its life, the sensor cannot be used even if connected by USB, so the battery will need to be replaced. Go Direct® 300 mAh Replacement Battery (GDX-BAT-300)
5. See How do I remove or replace a Go Direct battery? for more information.

Rechargeable batteries are covered by a one-year warranty.
Batteries should last two to five years in typical use.