Specifications

Manual # 016-0159-894 Rev H 01/07
305
A P P E N D I X
C
CALCULATING AND VERIFICATION OF
SPREADER CONSTANT
Calculation of
Spreader
Constant
For RATE displayed in 1 lb. [1 kg] increments:
L = Length in inches [centimeters] of belt travel per 1 revolution of the encoder
GH = Gate Height in inches [centimeters]
GW = Gate Width in inches [centimeters]
English (US): Metric (SI):
Spreader Constant = 311,040 Spreader Constant = [18,000,000]
1 lb. L x GH x GW [1 kg] [L] x [GH] x [GW]
Example: L = 13 inches [33 cm], GH = 7 inches [18 cm], GW = 15 inches [38 cm]
English (US):
Spreader Constant (1 lb.) = 311,040 311,040
13 x 7 x 15 1365 = 228
Metric (SI):
Spreader Constant (1 kg) = 18,000,000 18,000,000
[33] x [18] x [38] [22,575] = [797]
Verification of
Spreader
Constant
To verify and refine the spreader constant, perform the following procedure after
completing the initial setup of the Viper system.
1. Weigh loaded truck and record weight.
2. Enter the product density in lbs/cu. ft. [grams/liter] into the Density field in
the Data Box 2 section.
3. Set the total volume to zero for the product node being tested.
4. With the product node in the MAN position, unload a portion of the load by
positioning the boom switch to ‘ON’.
5. Determine the actual weight unloaded by re-weighting the truck.
6. Compare this weight to the total volume displayed on the Viper display.
7. Perform the following calculation to correct the spreader constant, if
desired:
Corrected Spreader Constant = [Old Spreader Constant x Total
Volume]/Acutal Weight Unloaded