Data Sheet

Page 3
Web: www.maxbotix.com
PD11500k
MaxBotix
®
Inc.
Copyright 2005 - 2012 MaxBotix Incorporated
Patent 7,679,996
HRXL-MaxSonar
®
- WR/WRC
™
Series
MaxBotix Inc., products are engineered and assembled in the USA.
About Ultrasonic Sensors
The HRXL-MaxSonar-WR ultrasonic sensors are in-air, non-contact object detection and ranging sensors that detect
objects within an area. These sensors are not affected by the color or other visual characteristics of the detected object.
Ultrasonic sensors use high frequency sound to detect and localize objects in a variety of environments. Ultrasonic sensors
measure the time of flight for sound that has been transmitted to and reflected back from nearby objects. Based upon the
time of flight, the sensor outputs a range reading.
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Device Comparison
Notes
1
exceeds the ability of the first generation XL-MaxSonar-WR models MB70##. Also includes target size compensation, internal temperature sensor, external temperature
sensor, factory calibration, supply voltage droop compensation, continuous automatic calibration, and side lobe suppression.
2
Higher gain and other calibration allows better performance to soft targets.
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Auto Calibration
Each time a HRXL-MaxSonar-WR series sensor takes a range reading, it calibrates itself. The sensor then uses this data to
range objects. If the temperature, humidity, or applied voltage changes during sensor operation, the sensor will continue to
function normally over the rated temperature range while applying compensation for changes caused by temperature and
voltage.
Target Size Compensation
Most low cost ultrasonic rangefinders will report the range to smaller size targets as farther than the actual distance. In
addition, they may also report the range to larger size targets as closer than the actual distance.
The HRXL-MaxSonar-WR sensor line compensates for target size differences. This means that, provided an object is
large enough to be detected, the sensor will report the same distance, typically within 1%
1
, regardless of target size
1
.
Smaller targets can have additional detection noise that may limit this feature. In addition, targets with small or rounded
surfaces may have an apparent distance that is slightly farther, where the distance reported may be a composite of the
sensed object(s). Compensation for target size is applied to all range outputs: pulse width, analog voltage, and serial
format output by the sensor.
Supply Voltage Compensation
During power up, the HRXL-MaxSonar-WR sensor line will calibrate itself for changes in supply voltage. Additionally,
the sensor will compensate if the supplied voltage gradually changes.
If the average voltage applied to the sensor changes faster than 0.5V per second, it is best to remove and reapply power to
the sensor.
For best operation, the sensor requires noise free power . If the sensor is used with noise on the supplied power or ground,
the readings may be affected. Typically adding a 100uF capacitor at the sensor between the V+ and GND pins will correct
most power related electrical noise issues.
Part
Number
Serial
Interface
First
Detectable
target
Most
Likely
Filter
High
Performance
HR Filter
1
Optimized
for snow
depth
Alternative
Packages
available
Soft/Small
Target
Detection
2
5 Meter
Range
10 Meter
Range
MB7360 RS232 Yes Yes Yes Yes
MB7363 RS232 Yes Yes Yes Yes
MB7364 RS232 Yes Yes Yes Yes Yes
MB7366 RS232 Yes Yes Yes
MB7369 RS232 Yes Yes Yes Yes
MB7380 TTL Yes Yes Yes Yes
MB7383 TTL Yes Yes Yes Yes
MB7384 TTL Yes Yes Yes Yes Yes
MB7386 TTL Yes Yes Yes
MB7389 TTL Yes Yes Yes Yes
Notes:
1
Refer to section that compares WR to WRC on page 4