D = distance from the sensor to the target

c = speed of sound in air

t = transit time for the ultrasonic pulse

To improve accuracy, an ultrasonic sensor may average the results of several pulses before outputting a new value.

Temperature Effects

The speed of sound is dependent upon the composition, pressure and temperature of the gas in which it is traveling. For most

ultrasonic applications, the composition and pressure of the gas are relatively fixed, while the temperature may fluctuate.

In air, the speed of sound varies with temperature according to the following approximation:

In metric units:

In English units:

C

Temperature Compensation

Changes in air temperature affect the speed of sound, which in turn affects the total time for the echo measured by the sensor. An

increase in air temperature shifts both sensing window limits closer to the sensor. Conversely, a decrease in air temperature shifts

both limits farther away from the sensor. This shift is approximately 3.5% of the limit distance for a 20° C change in temperature.

The K50U series ultrasonic sensors are temperature compensated, to reduce sensor errors from temperature by about 90%.

Exposure to direct sunlight can affect the sensor’s ability to accurately compensate for changes in temperature.

LED Indicators

Signal LED (red)

Power LED (green)

Power is Off

Off

Sensor is operating normally (power is on, sensor is in Run mode)

Flashing

Serial Communications Transmit/Receive

Intermittent Flashing

Error

Continuous Flashing

Reserved

Off

Self-Diagnostic Error Mode—In the unlikely event of a microprocessor memory error, the Signal LED continuously flashes. If this

occurs, the setup parameters have been lost and the sensor may be corrupt. Contact your Banner representative for further

information.

Sensor Configuration Tool

The Sensor Configuration Tool offers an easy way to manage sensor parameters, retrieve data, and visually show sensor data from

a number of different sensors. The Sensor Configuration Tool software runs on any Windows machine and uses an adapter cable

to connect the sensor to your computer.

Download the most recent version of the Sensor Configuration Tool from Banner Engineering's website:

www.bannerengineering.com/wireless. The Sensor Configuration Tool currently supports the following sensors:

Sensor Type

Model

USB Adapter Cable

Temperature and Humidity

M12FTH3Q and M12FT3Q

Model BWA-HW-006: USB-to-RS-485 adapter cable OR

Model BWA-UCT-900: USB to RS-485 adapter cable

M12FTH4Q and M12FT4Q

Model BWA-USB1WIRE-001: USB-to-RS-232 1-Wire adapter cable

Vibration and Temperature

QM42VT1

Model BWA-USB1WIRE-001: USB-to-RS-232 1-Wire adapter cable

QM42VT2

Model BWA-HW-006: USB-to-RS-485 adapter cable OR

Model BWA-UCT-900: USB to RS-485 adapter cable OR

When updating the firmware, you must use one of the two USB to RS-485 adapter cables plus a

splitter pigtail cable p/n 83265

2

www.bannerengineering.com - Tel: +1-763-544-3164

P/N 191599 Rev. F