Fluke 2180A - Manual (Page 20)

2180 A
2-17. The following paragraphs describe various
conditions
that could affect operation of the
thermometer. The operator should familiarize himself
with these conditions prior to operating the 2180A.
2-18. Option Information
2-19. Supplementary operating instructions are
necessary when operating the 2180A equipped with one of
the available options. Detailed information regarding the
operation of each available option is given in Section 6 of
this manual, Option and Accessory Inforamtion.
2-20. Fuse Replacement
2-21. The ac line input and external dc input are
individually fuse protected. Both fuses are readily
accessible on the outside of the rear panel. The ac line
input fuse (FI) should be replaced with a 1 /8A MDL(slo-
blo) fuse if either 100 or 120 volt operation has been
selected. Usea 1/16A MDL(slo-blo) replacement for 220
or 240 volt operation. The external dc input (F2) requires
a 3/4A MDL (slo-blo) fuse for a replacement.
CAUTION
Remove the power connector from the 2180A
before changing fuses.
2-22. RTD Installation
2-23. Use the following procedure when installing an
RTD and conducting temperature measurements:
1. Set POWER switch to OFF.
2. Remove the RTD Input Module from the
instrument (rear panel).
3. Route the selected RTD lines through the Input
Module’s rear access port, and connect them to the
input terminals; depending on the type of RTD,
connections may involve 2, 3, or 4 wires. Refer to
Figure 2-2 as a reference when connecting RTD
lines to the Input Module (TBl). Lines of the same
color usually go to the same polarity connections
(T-V and TS, or -V and -S). Refer to instructions
included with the RTD for specific connection
directions.
NOTE
When 2- or 3~wire RTDs are used, there is
some error created due to the RTD excitation
current in the Sense (S) wire leads. To
minimize this error. The user should (when
possible) use the 4-wire RTD connection as
show in Figure 2-2.
2-16. OPERATING NOTES 4. On the Input Module, toggle the RTD SekOi
Switch (S1) to obtain the desired RTD type, see TD
2
-
2
.
NOTE
The RTD Input Module may be printed with
microcomputer Type 41 selector switch set­
tings. Refer to Table 2-2 when changing RTD
types.
5. Slide the Input Module, RTD lines attache
back into the 2180A securely.
NOTE
Refer to Section 6 of this manual or applicable
accessory manuals for instructions on the
operation of any installed options or
connected accessories.
6. Set POWER switch to ON.
7. Expose the RTD to a temperature within the
RTD’s specified range (see Specifications in Section
1
).
8. The RTD temperature, in the scale selected, is
displayed on the front panel.
NOTE
R2 on the 2180A is adjusted at the factory
with a 100 ohm input resistance. If the 2180A
is used with a 100 ohm 385 Pt RTD probe
meeting DIN standard 443760, then the R2
adjustment in the following paragraph may be
ignored.
9. Adjust R2 on the RTD Input Module to com­
pensate for variations in lead resistance and in RTD
probe Ro values. Refer to Section 4 for RTD
input
module adjustment procedures. This adjustnieni
must be performed when an RTD probe is initially
installed and whenever the leads or the RTD
are
changed.
NOTE
The RTD adjustment can be used to calibrate
the 2180A and the probe near a specific
temperature. Adjust R2 for compatibility
between the 2180A and a customer supplied
temperature reference.
2-4