Metek RCT 10 series, Installation And Operating Instruction

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RCT 10, 11, 12, 13 Series
64
TRANSMITTER TEST - Using a 268 or 275 Handheld
WITHOUT a Device Description (Generic Mode)
1. Visually verify the span range of the electronic
unit.
2. Using the C-box, adjust the capacitance until 4 mA
is achieved. Record value . See Figure 6-2
3. Adjust C-box capacitance until 20 mA is achieved.
Record value.
4. Using Figure 6-3 , verify that the capacitance value
recorded at 20 mA is less than the MAX pF value
for the Span Range Position of the electronic unit.
5. Verify that the loop configuration is Level Config
(signal output linear to level vs. Vessel Config).
6. Subtract pF value recorded for 4 mA from the pF
value recorded for 20 mA. Divide this number in
half.
Example: 4 mA = 120 pF
20 mA = 800 pF
800 pF – 120 pF = 680 pF
680 pF ÷ 2 = 340 pF
7. Adjust the capacitance box (C-box) to the
number figured in step 6. The signal should read
approximately 50%.
8. If the display reads 50%, the unit is working
properly. If the display is not accurate, contact the
Service department at 1-800-527-6297 for further
assistance.
SPAN JUMPER POSITION
RANGE 1 2 3 4 5 6
MAX pF 20 100 450 2000 10000 40000
Figure 6-3
Span Range Capacitance Values
6.6 Troubleshooting Transmitter (Continued)
6.6.1 Transmitter Drift Test
If symptoms point toward calibration drift, it is important
to determine if the apparent drift is coming from the
transmitter, the sensing element, or the application
of the equipment. The following test determines if the
transmitter is stable. In most cases, no drift will be found
in the transmitter.
Figure 6-2
GROUND PROBE PAD SHD
RANGE SPAN
SPARE 1 2 3 4 5 6
C-Box
Transmitter