Service Information
4-2
• Use dry nitrogen gas to clean dust off the board if nec-
essary.
4.2.2 Soldering precautions
Should it become necessary to use solder on the circuit
board, observe the following precautions:
• Use an OA-based (organic activated) flux, and take care
not to spread the flux to other areas of the circuit board.
• Remove the flux from the work areas when the repair
has been completed. Use pure water along with clean
cotton swabs or a clean, soft brush to remove the flux.
• Once the flux has been removed, swab only the repaired
area with methanol, then blow dry the board with dry
nitrogen gas.
• After cleaning, the card should be allowed to dry in a
50
°
C low-humidity environment for several hours be-
fore use.
4.3 Performance verification
The following paragraphs discuss performance verification
procedures for the Model 2001-TCSCAN, including reference
junction, path resistance, contact potential, and isolation.
CAUTION
Contamination will degrade the perfor-
mance of the card. To avoid contamina-
tion, always grasp the card by the side
edges and covers. Do not touch connec-
tor insulators, board surfaces, or com-
ponents.
NOTE
Failure of any performance verification
test may indicate that the scanner card is
contaminated. See paragraph 4.2 for infor-
mation on cleaning the card.
4.3.1 Environmental conditions
All verification measurements should be made at an ambient
temperature between 18
°
and 28
°
C, and at a relative humid-
ity of less than 70%.
4.3.2 Recommended equipment
Table 4-1 summarizes the equipment needed for performance
verification and calibration (covered in paragraph 4.4). The
Model 2001 DMM is used in the procedures. However, you
can also use the Model 2000, 2002, or 2010. If using the Mod-
el 2000 or 2010, you may have to alter some procedure steps
slightly.
4.3.3 Scanner card connections
Jumper wires or connecting cables can simply be hard-wired
directly to the screw terminals of the Model 2001-TCSCAN.
Detailed connection information is provided in Section 2.
4.3.4 Reference junction test
This procedure verifies that the Model 2001-TCSCAN card
is operating within its temperature specification. The Model
2001 Multimeter is used to close Channel 1 of the card.
A second DMM must be used to make the voltage measure-
ments because the Model 2001 will not meet specifications
with the cover removed.
1. Remove the top shield from the Model 2001-TCSCAN,
and install it in the first Model 2001. Remove the Model
2001 cover to allow access to the card (see paragraph
4.7.2).
2. Turn on the second Model 2001, and set it to the
200mVDC range. Short the test lead ends together. Zero
the multimeter after the thermals have stabilized (one
hour if from cold-start).
3. Set up the test equipment as shown in Figure 4-1, and let
it warm up one hour. Be sure to protect the card from air
drafts. Use a probe with a specified accuracy of
±
0.005
°
C. The combination of the probe and reference
thermometer should be accurate to
±
0.03
°
C.
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