APG DCR-1006 user manual - Manual (Page 27)

Rev. A4, 10/08 DCR-1005 and DCR-1006
27
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Example: Calibration
1 Point Calibration
The Calibration Factor is used to bring the displayed reading in line with the
measured distance. To obtain the measured distance, measure from the level to
be detected to 0.5 in. behind the DST face. (0.5 in. behind the DST face is the
electrical zero of the sensor.) The calibration factor is determined by dividing the
actual distance measured, by the displayed distance. Enter this number in the
calibration modes 38 and 39.
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 = DCR 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 38 and 39. 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 36 and 37.