Yokogawa DM8C/VD6 Liquid Density Analyzer - Manual (Page 54)

< 4. OPERATION >
4-12
IM 12T03A01-02E
4.5 Operation
4.5.1 Operation Procedure
Start the density measuring system, and monitor operating conditions for a while to confi rm that there
is no abnormality. Adjustment for the density measuring system during operation is unnecessary,
however, daily check of liquid fl ow rate and pressure is preferable. When the steam tracing pipe is
installed in the sampling unit, do not heat the detector.
If an error indication is displayed, make a countermeasure immediately. Errors are listed in Table 4.2.
Table 4.2 Error Table
Display Contents Error Release and Remedy
E001 Abnormal detector density signal When cause is removed
E002 Abnormal detector temperature sinal
When cause is removed E003 Abnormal on converter
E004 Overrang of measuring temperature
E005 Abnormal fi rst calibration
Check and reset the data required for
calibration.
E006 Abnormal second calibration
E007 Illegal data of EEPROM Check and reset the loaded constant
(Note) E001, 002, 003, 004 and 007 are cancelled temporally by pressing the FUNCTION No. key
in maintenance or calibration mode, however in the measuring mode, the error indication is
displayed again. These errors are detected only in the measuring mode.
E005 and 006 occur only in the calibration mode and are displayed for one second when
calibration computation fi nishes and are cleared. After that, the density at the reference
temperature by the previous calibrating data is displayed.
4.5.2 Check of Measured Density Value
It is recommended that measured density values are checked at intervals of several weeks to
determine the period for calibration and cleaning.
(1) Measure the density using a hydrometer to compare it with the density indication (at the
reference temperature) on the vibration type density meter. When sampling the liquid, check the
pressure and the temperature are not largely different from those of the normal state.
(2) Measure density correctly at the reference temperature which is same as the sample liquid
temperature.
(3) Compare the density measured at (2) with the displayed value when sampling the liquid. If the
difference of them exceeds the allowable error range, clean the vibrator.
For cleaning procedure, refer to Section 5.1.1.
4.5.3 Shutdown
When shutdown sample following steps and the vibration type density meter also stops, drain the
sample from the detector.