FUTEK VCal Sensor Verification - Manual (Page 43)

Futek Advanced Sensor Technology – Futek VCal™Documentation Rev. 1.8.0 07/26/05
©Futek Advanced Sensor Technology 2005 43
Test Parameters
Under the Test Parameters section of the Setup tab there are are options for defining the number of Load Points (required to perform a test),
Averaging, Decimal Points, and Target Load Warning Tolerances.
Load Points: This field is required to perform a calibration or test. This is where you define how many points in the load range you will take
readings at. For example; if your cell is rated at 500 lbs, your calibration load is also at 500 lbs, and you set
Load Points to 5, your Load Points
will be 100, 200, 300, 400, and 500 lbs.
Averaging: The number you enter here determines the number of readings VCal™ will take when you press Enter, and then return an output
value that is an Average of all the output readings taken.
Decimal Points: This setting is where you determine the resolution of the data points. This box is only used with the Manual Entry mode of
calibration. Under normal calibration or testing circumstances the number of decimal points will be determined by the resolution of the display.
Target Load Warning Tolerance: This setting allows you to set a tolerance level with regards to your load points, so that VCal™ will issue a
warning that you are within the tolerance level you have set of your load point. For example; if your first load point is 50 lbs, and you have your
Target Load Warning Tolerance set to 1, then when you increase the load applied to 49 lbs, VCal™ ‘s display screen background will change
from Black to Yellow to let you know that you are within the 1 lb tolerance level you have set. The number you enter in the Tolerance box is
an increment of whatever units you are measuring your load with. If you enter a 2 in the box, and you are measuring your load in kilograms; then
VCal™ will issue a warning when the load applied is within 2 kgs of the load point.
Test Conditions
The final section of the Setup tab is the Test Conditions section. Here is where you decide whether to perform your calibration using
VCal™’s Auto Read function, or maybe to read from an RS232 device, and also where you decide whether to test for Linearity or Linearity
and Hysteresis.
Auto Read: By selecting this option you are telling VCal™ that you wish to utilize the Automatic Reading Taking function. This feature
works like a normal calibration except that you do not need to press
Enter as you reach each Load point. With Auto Read selected you
simply start loading your sensor, and as you reach each load point indicated in the Test Grid, VCal™ will automatically take a reading
and display the corresponding outptut value in the Output column of the Test Grid.
Read from RS232: This setting allows you to read from an externally connected RS232 device (such as the Futek D500 series displays),
and display the data on your VCal™ display.
Linearity: With this type of calibration, VCal™ takes a reading every time you press Enter on the ascending loading of your sensor, returns
an output value to the Test Grid, and calculates the non-linearity error based on your output’s deviation from the ideal value at that load point.
Hysteresis: With this type of calibration, VCal™ takes a reading every time you press Enter on both the ascending and descending loading
of your sensor, returns output values for each point, and then calculates the error based on the differences between the ascending and
descending output values at each load point.