American Hakko Products, Inc.
28.
When finished, turn off the HAKKO FG-101. Ensure the source supply is stopped on the
Yokogawa CA-71 Portable Calibrator or equivalent device and remove the source leads from the
HAKKO FG-101. Ensure the switch on the PCB (SW 1) is set to the WHITE (X) position and turn
off the HAKKO FG-101. Re-secure the two halves of the unit by installing the 5 Phillips screws
along the front and rear of the casing.
Ground Resistance Measurement Calibration
1.
Plug in the HAKKO FG-101 and turn the unit on.
2.
Select the OHM measuring mode on the HAKKO FG-101.
3.
Hold the AUTO ZERO button for at least 3 seconds until the LCD display shows 0, ‘mV’, and ‘
Ω
’,
then release the button.
4.
Press the AUTO ZERO button again and the LCD display will show -1, ‘.’ and ‘
Ω
’.
5.
Open the HAKKO FG-101 by removing the 5 Phillips screws along the front and back of the
casing.
6.
Carefully separate the two halves of the unit, tipping the top half of the unit towards you and
resting it upside down, revealing the PCB.
7.
Connect the Yokogawa 2786 Decade Resistance Box or equivalent device to the PCB where one
test lead is connected to the grounding terminal of the HAKKO FG-101, and the other test lead
is connected to the screw used to secure the test plate of the HAKKO FG-101. The two screws
that secure the test plate are visible underneath the PCB through a hole and notch that are in
the PCB by design. It is recommended that you make the connection of the red source lead to
screw that is on the right-hand side from your view, and is exposed by the notch designed into
the PCB.
8.
Set the Yokogawa 2786 Decade Resistance Box to a resistance value of 0.
9.
Adjust VR5 on the PCB so that the display on the HAKKO FG-101 is showing a value of 0.0
Ω
.
10.
Set the Yokogawa 2786 Decade Resistance Box to a resistance value of 40.
11.
Adjust VR4 on the PCB so that the display on the HAKKO FG-101 is showing a value of 40.0
Ω
.
12.
Remove the test leads of the Yokogawa 2786 Decade Resistance Box from the PCB.
