Data Sheet

Page 4
Web: www.maxbotix.com
PD11721m
MaxBotix
®
Inc.
Copyright 2005 - 2014 MaxBotix Incorporated
Patent 7,679,996
HRLV-MaxSonar
®
- EZ
™
Series
MaxBotix Inc., products are engineered and assembled in the USA
Supply Voltage Droop and Charge Compensation
During power up, the HRLV-MaxSonar-EZ sensor line will calibrate itself for changes in supply voltage. Additionally,
the sensor will compensate if the supplied voltage gradually changes.
If the voltage applied to the sensor changes faster than 0.5V per second, it is best to remove and reapply power to the
sensor.
The sensor requires noise free power for best operation. If the sensor is used with noise on the supplied power, 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.
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Mechanical Dimensions
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Temperature Compensation
On Board - Internal Temperature Compensation
The speed of sound in air increases about 0.6 meters per second, per degree centigrade. Because of this, each
HRLV-MaxSonar-EZ is equipped with an internal temperature sensor which allows the sensor to apply a compensation
for speed of sound changes.
The self heating (15mW at 5V, or 8mW at 3.3V) will change the temperature of the sensor by about 1 degree C. The
amount of self heating is dependent upon user mounting.
Most importantly, the actual air temperature of the path between the sensor and the target may not match the temperature
measured at the sensor electronics. Sensors mounted in vertical applications, or applications where the environmental
temperature gradient is severe, may experience a large temperature measurement error which will effect the sensor
accuracy. For example, buildings with a height of 2-meters can have floor to ceiling temperature variations of 5°C or
more. Because of these temperature effects, users desiring the highest accuracy output are encouraged to use a properly
mounted external temperature sensor or to manually account for this measurement error.
HR-MaxTemp
®
External Temperature Sensor
Although the HRLV-MaxSonar-EZ has an internal temperature sensor; for best accuracy, users are encouraged to use the
optional external temperature sensor. On power-up the HRLV-MaxSonar-EZ will automatically detect an attached
HR-MaxTemp temperature sensor and begin to apply temperature compensation using the external temperature sensor.
The external temperature sensor allows for the most accurate temperature compensation, by eliminating sensor
self-heating from the sensor electronics, and by allowing the user to place the temperature sensor closer to the center of
the acoustic ranging path.
For best results users are encouraged to connect the temperature sensor midway between the HRLV-MaxSonar-EZ and
the expected target distance.
Paint Dot Color
Black Brown Red Orange Yellow
Part Number
MB1003 MB1013 MB1023 MB1033 MB1043
Paint Dot & Location