YOKOGAWA vigilantplant DM8, User Manual

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<4. OPERATION>
4-8
IM 12T03A01-02E
(5) Fully open “BV1” and “NV4” and half open “NV1” in the sampling unit. Close ‘drain’ valve
opened in (3). Gradually open the ‘tap’ valve located on the sample inlet conduit. As sample
begins to flow out of the ‘drain’ valve on the sample return conduit, fully open the ‘stop’ valve
and fully close the ‘drain’ valve when no retaining air is found in the liquid.
(6) Open “NV2” to exhaust retaining air in the pipe. When the sample liquid without air flows out
from the ‘drain’ port, fully close the “NV2”.
(7) Adjust opening of NV1 to make sample flow rate approx. 5 L/min for the detector.
Flow rate shown by FM in the VD6SM sampling unit of Yokogawa varies according to
viscosity of sample. If the viscosity of sample liquid becomes higher, flow rate indication also
becomes higher than real flow rate (see Figure 4.4).
0
5
10
15
20
5 10 15 20
Actual flow rate (L/min)
Indication of flowmeter (L/min)
Specific gravity of liquid ( ρ =0.85)
15 cP
10 cP
5 cP
1 cP
20 cP
25 cP
30 cP
35 cP
40 cP
50 cP
60 cP
Figure 4.4 Flow Rate Characteristics for Sample Liquid Viscosity
(8) Confirm that the sample liquid temperature T and pressure P are in the specified range.
(9) Visually check that the sample liquid is not leaking from the connections.
4.3.4 Turning ON the Power
Supply the converter and a receiving unit (recorder, computer, etc.) with power with specified
voltage and frequency. The receiving unit should be ready to receive the data and controller
should be adjusted to perform accurate control.
4.3.5 Data Input
Set the mode transfer switch to “MAINT” (maintenance mode) and input data to the function No.
‘6.’, ‘7.’, ‘8.’, ‘9.’, ‘A.’ and ‘B.’. For details of data to be input, refer to Section 4.2. Data is input with
“SHIFT►”, “INCR▲” and “SET” keys. For details of these keys operation, refer to Figure 4.1.2.
When temperature coefficient of measuring liquid that is to be input into function No. ‘9.’ is
unknown jet, refer to ‘4.4.2 Calibration with Sample Liquid (2)’.
5th Edition : Dec. 11, 2015-00