Yokogawa DM8C/VD6 Liquid Density Analyzer - Manual (Page 55)

< 5. MAINTENANCE >
5-1
IM 12T03A01-02E
5. MAINTENANCE
5.1 Daily Inspection/Maintenance
5.1.1 Cleaning the Vibrator in the Detector
Dirt particles may be deposited on the inner wall of the vibrator pipe, depending upon the nature of the
process liquid. This can cause an error. Clean the pipe at regular intervals in the following manner.
(1) Close valves BV1 and NV4 and open NV2 and NV3.
(2) Connect the air pipe to the outlet of the needle valve NV2. Purge the sample liquid in the vibrator
from the drain port of the needle valve NV3 by blowing 0.05 MPa G air.
(3) Remove the blind plugs from the pouring port of the standard solution (two places) and pour
cleaning liquid about 200 ml into the vibrator.
(4) After a while, fi x blind plugs again on the pouring ports and purge the cleaning liquid in the
vibrator as described in (2). Wash the inside of the vibrator pipe with a brush (accessory) as
shown in Figure 5.1.
STEAM IN
CONDENSATE OUT
V2
a
a
V1
b
ST1
a'
a'
b'
TI
F
FM
NV1
PI
NV2
DD
NV3
NV4 BV1
Element specifications
F: Strainer body; SUS316
Element; SUS316, or Ni (option)
PI: Pressure gauge, 0 to 1MPa or 0 to 2MPa, SUS316
TI: Thermometer. 0 to 100 °C or 0 to 150 °C, SUS316
FM: Flowmeter, tapered metal tube flowmeter, 1 to 10 l/min, SUS316
BV1: Ball valve, SUS316
NV1 to 4: Needle valve, SUS316
DD: Density
detector
V1, V2: Valve
ST1: Steam trap
SAMPLE IN
SAMPLE OUT
Figure 5.1 Cleaning the Vibrator Figure 5.2 Flow Diagram
(5) Remove the blind plugs again from the pouring ports of the standard solution and pour the
cleaning liquid about 200 ml. After a while, fi x the blind plugs and purge the sample liquid by
blowing 0.05 MPa G air. After the liquid is blown out, increase the air pressure up to 0.2 to 0.3
MPa G blowing air for 2 or 3 minutes to dry the inside of the vibrator.
5.1.2 Exchange of Desiccant in the Detector
Desiccant is used to protect the oscillation amplifi er in the detector from humidity.
Checks the detector terminal box one or two times a year and replace the desiccant if humidity is
detected. Two desiccants are provided as accessories. For the explosionproof detector, confi rm that
there are no explosive gases using a gas detector before removing the terminal box cover.