SensComp Cricket-A User manual

General
This operation and installation manual provides
general guidelines and suggestions to assist
you in using the SensComp, Inc. Cricket-A
ultra-sonic sensor module in many
measurement applications. For additional
information, please contact SensComp at
www.senscomp.com or [e-mail] .
General Installation Procedures
1. Always mount the Cricket-A sensor in a
suitable dry location. The Cricket-A is
designed to be used indoors or in protected
environments only. Excessive moisture on
the circuit board (and the sensors
transducer) will result in damage and
improper operation, and will void all
warranties.
2. Mount the sensor as vertically as high as
practical above all horizontal surfaces. The
sensor detection area is cone shaped at a
17 degree angle and the further the sensor
is away from the target the larger the
diameter the detection area is. This will help
to avoid false detections.
3. Mount the sensor in a location where
environmental interference sources are
minimized (examples are EMI sources, air
nozzles, excessive air turbulence, etc.).
4. Mount the sensor using (2) #6-3/4” or longer
screws.
5. As shipped from the factory, the sensor has
been calibrated for maximum and minimum
range; user will need to set desired ranges
as needed.
System Wiring Information
Brown Wire – Power Supply – supplying 30 mA of
current (2.0 Amperes during the 0.5 ms
transmit pulse).
•The 0 to 5 VDC analog output model
requires a +8 to +24 VDC regulated power
source.
•The 0 to 10 VDC analog output model
requires a +12 to +24 VDC regulated power
source.
Blue Wire – Power Supply Common (Ground) –
Common Return for DC power supply, analog
output.
Black Wire – Analog Output – 0 to +5 VDC (or 0 to
+10 VDC) analog voltage output. Maximum
analog output current is 5 mA.
White Wire – No connection.
See Figure 1.
Calibration Procedures
Note: The Cricket-A Sensor is calibrated before it
leaves the factory for the following settings:
•0 - 12 inch version:
•[0 volts = 1 inch; max volts = 12 inches]
•6 “- 20 foot version:
•[0 volts = 6 inches; max volts = 20 feet]
The following information provides calibration
techniques to obtain a more precise analog volt-age
output, setting the minimum and maximum target
points, and adjusting the receiver gain of the
returning echo signal.
1. Apply DC power (see requirements above) to
the sensor).
2. Connect a DVM set to DC volts, Plus (+) lead to
the Analog Output (Black Wire) and the Minus (-
) lead to Common (Blue Wire).
3. Allow 3 -5 minutes warm-up time for the sensor
to reach operating temperature before
calibrating the unit.
4. Setting Minimum/Maximum Ranges
Two push-button switches set the Cricket-A
output voltage. These independent range
settings allow setting the analog voltage
output to change from zero volts to full
scale voltage output at the desired
minimum and maximum distances
between the sensor and the detected
object.
5. Maximum Voltage Range Setting
•Place the target at the desired distance
for the full scale voltage output. This
can be either the minimum distance or
the maximum distance between the
sensor and the target (see step 4).
•Depress and hold the “MAX SET” push
button for about 3 seconds, until you
here a “chirp” sound and then release
the push button. This indicates the
range is set.
The sensor is now calibrated to your de-
sired target distance for full scale analog
voltage output.
6. Minimum Voltage Range Setting.
•Place the target at the desired distance
for the minimum voltage output. This
can be either the minimum distance or
the maximum distance between the
sensor and the target (see step 5).
•Depress and hold the “MIN SET” push
button, for about 3 seconds, until you
here a “chirp” sound and then release
the push button. This indicates the
range is set.
The sensor is now calibrated to your de-
sired target distance for 0.00 analog
voltage output.
9Note: The minimum voltage output will
be a value between 0.00 and 0.05 volts
(50 mV), due to the analog output’s
amplifier offset voltage.
•The sensor is now calibrated to your
desired target distance for zero analog
voltage output.

7. Gain Adjustment
Note: The “GAIN” potentiometer has been
preset at the factory to provide the best
performance for the range of your Cricket-A
sensor. In the event that it is changed, the
steps below will assist you in returning it to
the proper value
•To calibrate the “GAIN”, place the target
at the maximum desired detection
distance.
•Rotate “GAIN SET” fully counter clock-
wise (CCW).
•Slowly rotate “GAIN” clockwise (CW) until
detection occurs.
Rotate “GAIN
SET” clockwise (CW) an additional 1/16
turn.
9Note: Always calibrate “GAIN SET” for
minimum gain required for reliable
detection. Excessive gain may result in
false target detection.
Detect LED
The Detect Range LED performs two indication
functions:
•During the range setting procedures, the
LED will flash as the range values are
programmed into the sensor.
•During normal operation, the LED will
illuminate, indicating that a target is
detected between the “Minimum Range”
set point and the “Maximum Range” set”
point. For targets outside this range, the
LED will be off.
FIGURE 1.
SensComp, Inc.
36704 Commerce Road
Livonia, MI 48150
Phone: [phone]
Fax: [phone]
www.senscomp.com
Copyright © 2007 SensComp, Inc.18 Sept 07
Cricket-A
Ultrasonic Sensor
Installation and
Operation
Manual