APG DCU-1100 user manual - Manual (Page 20)

DCU-1104 and DCU-1108 Rev. A2, 11/06
20
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to be in the far left position. So a value of 53 would correspond to 0.0053,
whereas 5300 would correspond to 0.5300.)
EXAMPLE:
The Calibration Factor is used to bring the displayed reading in line with the
measured distance. To obtain the measured distance, measure from the target to
be detected to .5 in. behind the DCU-11 face. (.5 in. behind the DCU-11 face is
the electrical zero point of the sensor.)
1 Point Calibration
The calibration factor is determined by dividing the actual distance measured
by the displayed distance. Enter this number in the calibration Modes 22 and
23. Then the displayed readings should match the measured distance.
2 Point Calibration
If a more precise calibration is required, a two point calibration should be
used. This is accomplished by using the linear equation of Y = AX + B where;
Y = measured distance X = DCU-11 reading
A = Multiplier B = Offset
The multiplier (A) can be determined by taking ultrasonic readings at two
known distances and dividing the difference of the known distances(D) by the
difference of the ultrasonic (U) readings (A) = (D
2
-D
1
)/ (U
2
-U
1
) where;
D
2
= far known distance U
2
= Ultrasonic reading at D
2
D
1
= close known distance U
1
= Ultrasonic reading at D
1
Enter this multiplier in Modes 22 and 23. The multiplier can then be entered
in the above equation to calculate the offset B = D
2
- (A)U
2
. The offset should
be entered using Modes 20 and 21.