VI-700 V&l Source
16
CALIBRATION
7.3.3 Current calibration
The voltage calibration of the above subsection must
be performed before this current calibration. The cali-
bration may be performed using an ammeter or a volt-
meter with a precision resistor. This latter method
may be preferable since an ammeter with the required
accuracy is not as common or convenient as a volt-
meter. If the voltmeter method is to be employed,
connect a stable 1 k
Ω
precision resistor, whose value,
is known to the required accuracy, securely across
the current output binding posts. In the instructions
below, follow the items in parentheses for the volt-
meter method
1. Attach the digital ammeter (voltmeter) leads
securely to the current output binding posts.
2. Set the VI-700 to 0.000 on the X0.1 range.
3. Adjust trimmer 1-T6 to obtain a current
(voltage) reading as close to zero as possible.
0.05
µ
A (50
µ
V) or less is satisfactory.
4. Set the VI-700 to 1.799 on the X10 range.
5. Adjust trimmer 1-T11 to obtain a current of
17.990 mA (voltage of 17.990 V).
6. Set the VI-700 to 1.799 on the X0.1 range.
7. Adjust trimmer 1-T7 to obtain a current of
179.90
µ
A (voltage of 179.90 mV).
7.3.4 High Current Output Calibration -
Optional
1. Attach the digital ammeter leads securely to
the current output binding posts.
2. Set the VI-700 to the X10 range.
3. Set the 200 mA pushbutton ON.
4. Set the thumbwheel switch to 1000.
5.
Adjust trimmer 1-Tl6 to obtain a current
reading of 100 mA.
7.3.5 Current Overload Indicator Setting
This is not a critical adjustment and may be bypassed
unless a problem is suspected.
1. Set the front panel to 1.999 on the X10 range.
2. Connect a l k
Ω
resistor whose value is
precisely known to the current output
connectors.
3. Adjust trimmer 1-Tl2 so that the current
OVLD
indicator is just about to come on.
