Cooper Instruments & Systems DFI 1650 Multi-Channel Digital Force Indicator - Manual (Page 61)

CF 66 55 Rev. C 2/05
“KNOWN POINT 4/5” and “KNOWN POINT 5/5” registers. This technique can be used to compensate for the
non-linearity in the transducer. The usual loads are zero scale, on-quarter scale, half scale, three-quarters
scale and full scale, but you are not restricted to these loads.
The selection of the calibration type affects what menu items appear in the CALIBRATION DATA sub-menu.
12.6.5 CALIBRATION DATA Sub-Menu
This enters the values that will be used by the instrument when it calibrates itself to the transducer. The menu
items that are displayed will change according to what the CALIBRATION TYPE is set for.
FULL SCALE VOLT or FULL SCALE CURR Menu Item
The nominal transducer/amplifier output when its full-scale load is applied to it, in volts or milliamps. This menu
item is used by the instrument to set gain of its amplifier circuit. This value is normally fond on the transducer’s
Certificate of Calibration or amplifier’s Application Note.
FULL SCALE VALUE Menu Item
The transducer’s full-scale output in engineering units. It is available only with the Shunt Calibration type.
ZERO SCALE VALUE Menu Item
The transducer’s zero-scale output in engineering units, which is usually zero. It is available only with the Shunt
Calibration type.
SHUNT CAL VALUE Menu Item
The shunt calibration value must be calculated by using information found on the transducer’s Certificate of
Calibration and the following formula:
SHUNT CAL VALUE = Shunt-Calibration Output/Full-Scale Output X Full-Scale Capacity
The terms have the following meanings:
• Shunt-Calibration Output: The transducer’s output when its shunt calibration function is activated in Volts or
milliamps. Sometimes called “Shunt Cal. Factor”.
• Full-Scale Output: The transducer’s full-scale output in Volts or milliamps. Sometimes called “Calibration
Factor”.
• Full-Scale Capacity: The transducer’s desired full0scale reading in engineering units (PSI, lbs, Kg, etc.). You
may wish to convert the engineering units of this value. For example, if the transducer full scale is 3000 PSIG
and you wish the channel to read in bar, you must convert 3000 PSIG into 206.84 bar.
This menu item is only available with the Shunt Calibration type.
To verify proper transducer/amplifier operation, you can activate the transducer’s/amplifier’s shunt calibration
function while the instrument is in the RUN mode. Press and hold the [ENTER] button for three seconds; this will
activate the transducer’s/amplifier’s shunt calibration function and display the reading.
KNOWN POINT x/y Menu Items
This enters the engineering units for the known-load calibration points. These points must match the actual loads
that you will apply to the instrument during calibration. The number of calibrations points depends on the
CALIBRATION TYPE.
When using the 2-Point Known Load Calibration type, the following menu items are available:
• “KNOWN POINT 1/2”: point 1 of 2, usually 0% of the transducer’s full0scale capacity.
• “KNOWN POINT 2/2”: point 2 of 2, usually 100% of the transducer’s full-scale capacity.
When using the 3-Point Known Load Calibration type, the following menu items are available:
• “KNOWN POINT 1/3”: point 1 of 3, usually 0% of the transducer’s full-scale capacity.
• “KNOWN POINT 2/3”: point 2 of 3, usually 50% of the transducer’s full-scale capacity.
• “KNOWN POINT 3/3”: point 3 of 3, usually 100% of the transducer’s full-scale capacity.
When using the 5-Point Known Load Calibration type, the following menu items are available: