Vernier Tech Info Library TIL #1374

Motion Detector Sensor Detail Information

Motion Detector, order code MD-BTD, $79.00
Specifications and User Guide

There are two Motion Sensor models:
Motion Detector 1 (MDO-BTD) - blue plastic, two LEDs below and to the left/right of the gold screen.
Motion Detector 2 (MD-BTD) - green plastic, one LED on the right below the gold screen, track mode switch inside pivoting head. (Began shipping 1/2005.)

TROUBLESHOOTING
- Test 1: Does a green LED light up after it is plugged-in and autoid'ed by a data-collection program, ?
- Test 2: With DataMate and Data Pro, do you hear a slow clicking to monitor distance? (To enable live monitoring in Logger Pro and Logger Lite, look in online help for "Live readouts".)
- Test 3: Point the Motion Detector at a flat wall with no objects within a 20 degree cone from the gold screen. Monitor or collect data and compare to your known distance from the wall.
- Tip 1: Optimum collection rate is 20 pts/second.
- Tip 2: Clear all objects within 20 degree cone.
- Tip 3: Tilt the head up slightly.
- Tip 4: Use track mode switch for cart on track. Use Normal mode for all other applications. It does no harm to try the other mode.
- Tip 5: Increase target's area.
- Tip 6: Noisy velocity data, increase the number of points used for derivative calculations.
- Tip 7: The maximum sample rate that you can use for the motion detector is 50 Hz, which equates to a sample interval of 0.02 seconds.

RELATED TIL ENTRIES
- TIL 5: My Motion Detector gives noisy readings or will not work at more than 2 m. What can I do about this?
- TIL 19: Can I use 2 motion detectors with my Vernier Interface?
- TIL 410: Can you create new match files for Logger Pro?
- TIL 405: Can I use a PASCO motion detector with the LabQuest, LabPro, CBL, or ULI interfaces?
- TIL 649: How do I calibrate a MPLI Motion Detector?
- TIL 459: What don't I get a freefall acceleration value of 9.8 m/s^2 when using a motion detector?
- TIL 318: Should I get a Motion Detector or a CBR?
- TIL 1009: Why are LabPro Motion Detector distances in Logger Pro sometimes offset by 1 meter?
- TIL 1001: How do you create new match files for MacMotion or Motion?
- TIL 1914: My motion detector still reads 0.004 m after zeroing.
- TIL 1938: Should I use a photogate or a Motion Detector?
- TIL 2053: How do I improve the results from a Motion Detector with an air track?

SPECIFICATIONS
- order code: MD-BTD
- ultrasound frequency: 50 kHz
- resolution: 1 mm
- accuracy: 2 mm
- range: MD-BTD - 0.15 m to 6 m
MDO-BTD - 0.5 m to 6 m
- speed of ultrasound used to calculate distance: 343 m/s *
- power: 51 mA while running

*Adjusting the "temperature" setting in Logger Pro changes this value. Speed increases with temperature. We apply a linear correction such that a 1 �C change of temperature is equal to 60 cm/s change of speed of sound. The Go! Motion is more sophisticated because only it has a built-in temperature sensor and applies the correction automatically.

CALIBRATION
- Air temperature corrections are possible only in Logger Pro and Logger Lite in the Sensors dialog.

RELATED VERNIER PRODUCTS
- Motion Detector Clamp, order code MD-CLAMP, $7.00, must order separately
- Motion Detector to LabPro/CBL Cable, order code MDC-BTD, $5.00, shipped with sensor
- Cable Motion Detector to MPLI, order code M-MDC, $5.00
- Cable Motion Detector to ULI, order code ULI-MDC, $5.00
- Motion Detector Bracket, order code MDB-VDS, $11.00
- Digital Extension Cable, order code EXT-BTD, $12.00, 2 m in length

Created by: jmcbride on February 03 2005
Last updated by: dvernier on August 20 2009