Go Direct^® Motion Detector (GDX-MD)
Specifications and User Guide

TROUBLESHOOTING
– Primary Test: Press the power button on the sensor to turn it on. (The red LED will flash.) Start the Graphical Analysis or Graphical Analysis Pro app on your device and select the sensor from the list of available sensors. (The green LED will flash.)
– Test 2: If the Motion Detector is not working when connected by USB, it may be the cable that is bad and not the sensor. Try a cable from a working unit.
– Test 3: To test accuracy, find a wall with no desks, chairs, doors, or other obstructions within a 2 m field. Hold the motion detector in your hand, 0.5 m from the wall with the sensor pointing directly at the wall. Do you get the expected 0.5 m reading? Back off to 1.0 m. Do you get 1.0 m? Back further off to 1.5 m. Do you get 1.5 m?

USAGE TIPS
– Tip 1: The optimum collection rate is 20 pts/second, and the maximum sample rate that you can use for the Go Direct Motion is 30 Hz
– Tip 2: Clear all objects within the 30 degree cone.
– Tip 3: Increase the target’s area, for example by taping an index card to the object such that the ultrasound will detect the flat surface of the card.

For more detailed usage tips, see Why am I getting Motion Detector readings that are noisy or max out at a certain distance?

SPECIFICATIONS
– Range:
Motion and Motion with TC channels: 0.25 m to 3.5 m
Motion (cart) channel: 0.15 m to 3.5 m
– Resolution: 0.001 m

CALIBRATION
– The Motion channel (which is the default channel) and the Motion (cart) channel are factory calibrated. You can calibrate these channels for better accuracy by placing a flat object such as a book, box, or wall a measured distance from the front surface of the sensor housing and performing a one-point calibration.
– The Motion with TC channel cannot be calibrated. It uses an internal temperature sensor to determine the speed of sound to be used in calculations.

Sensor dimensions:
– Length: 6.5 cm
– Width: 6.4 cm
– Height: 6.8 cm

RELATED TIL ENTRIES

OPERATION
Why am I getting Motion Detector readings that are noisy or max out at a certain distance?
Go Direct Sensor always reads zero (or some other constant value).
Why don't I get a freefall acceleration value of 9.8 m/s² when using a Motion Detector?
How does a Vernier Motion Detector work (electrically)?
Should I use a photogate or a Motion Detector?
How do I improve the results from a Motion Detector with an air track?
Will your Motion Detector show the speed of a (car, baseball, racquetball)?
How do I attach the Motion Detector bracket to the Vernier track?

CALIBRATION
Is there a way to calibrate a Motion Detector?

OTHER
Which motion detector should I buy? What are the differences between them?
Which Motion Detector model do I have?

BATTERY TROUBLESHOOTING
If the sensor can be turned on when connected by USB but not when disconnected from USB, it is likely that the battery just needs to be charged. In this case, charge the sensor for several hours and try again. If, however, the sensor won’t turn on regardless of whether the USB cable is connected or not, and you are confident that the USB cable is good by having tested it on another sensor, then the battery has likely reached its end of life and can no longer hold a charge. In this state, the sensor cannot be used even if connected by USB, so the battery will need to be replaced. The rechargeable battery in this sensor is covered by a one year warranty but should last two to five years in typical use. Note that if the battery is less than one year old and the sensor cannot be turned on even when connected by a working USB cable, another possibility is that the USB port is bad. In this case, contact Vernier technical support for assistance. 

REPLACEMENT PARTS
– Go Direct® 650 mAh Replacement Battery (GDX-BAT-650)
– Micro USB Cable (CB-USB-MICRO)

RELATED VERNIER PRODUCTS
– Motion Detector Clamp (MD-CLAMP)
– Go! Motion (GO-MOT)
– Motion Detector Bracket (DTS-MDB)
– Motion Detector (MD-BTD)
– CBR 2 (CBR2)