I N T E R F AC E M O D E L 9 8 4 0
MO D E L 9 8 4 0 P G 2 3
P U B .
6 0 3 2 - 0 1
torque are not disturbed since all the readings taken are averaged together to obtain
the calibration data. The second mass/torque is then entered and applied to the cell,
the Model 9840 will auto fill in this value based off the previously entered total rated
load of the cell and the amount of points the calibration requires. This auto filled value
is completely adjustable. Once all points are read, a "No Masses Ready?” or "No
Torque Ready" reading is also required. During this reading, a shunt check value is
recorded. It is essential that the cell not be under load or torque when this step is
performed.
>>Five Point Data Cal
Similar to the Two Point Data Cal above, this calibration option is used to calibrate a
load or torque cell using known masses or torques. The process will be the same as
the Two Point Data Cal but with added point measurement readings to total five. One
of the readings, usually the first, should still be zero and at the end of the point
measurement process a shunt check is performed designated by the "No Masses
Ready?” or "No Torque Ready" screen appearing.
>>Cal by Shunt Val
This item is used to calibrate a cell using the manufacturer’s shunt calibration factor
expressed in pounds or pound-inches. You will be asked, after the basic data
described above, for the shunt calibration constant. The Model 9840 will then
automatically perform the shunt calibration of the cell using its internal
precision shunt
resistor. Note that there is a back panel switch that allows you to select either a 30K
or 60K resistor for shunt measurements (see Appendix B for a circuit diagram). Be
sure to select the appropriate value for your cell. During this calibration the
“Reading...” message will be displayed. Do not disturb the cell while it is being read.
Like all the calibrations when a shunt check is performed, the cell should be free of
load or torque during this calibration.
