YOKOGAWA vigilantplant DM8, Руководство пользователя

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<4. OPERATION>
4-11
IM 12T03A01-02E
NOTE
(a) Time for calibration computation varies with density value difference between pre-calibration
and after-calibration. The larger the difference is, the longer the time is. It can take up to
about 7 minutes
(b) The density value after calibration doesn’t always coincide with the density of the standard
solution 1 even if they are compared in the same temperature.
Especially when the solution temperature during calibration largely different from the
reference temperature an error is apt to occur.
However, the error is usually within allowable range, if it is too large, examine each set
value.
(8) The first calibration is finished by (7). Then, use the standard solution 2 carry out the second
calibration whose procedure is same as the first calibration. Repeat the operations of (1) to
(7). For the calibration computation, set the function No. to ‘A’ (CAL-2 display flashes seven
times).
When the second calibration is finished, purge the standard solution from the vibrator and screw
the blind plug into the pouring port, fully close the needle valves “NV2” and “NV3” and remove the
connected air pipe.
4.4.2 Calibration with a Sample
Calibration with sample liquid should be made according to the following procedure.
(1) Sample the measuring liquid which is measured by a hydrometer. Sampling should be
made when the liquid density is stable.
NOTE
The density of the sample liquid should not change between sampling the liquid and finishing the
first calibration.
(2) Measure the density using the hydrometer and the temperature of the sampled liquid.
Examine the temperature coefficient if it is not known. Using densities at high temperature
(reference tempe approx. 5°C) and low temperature (reference temperature -
approx. 5°C), the temperature coefficient should be calculated as following.
Temperature coefficient (g/cm 3 /°C) =
(Density at high temperature – Density at low temperature)
/Difference between high and low temperatures
(Note): The density values should be those at the reference temperature as far as possible.
(3) Set the mode transfer switch of the converter to “CAL” and input the data corresponding to
function No. ‘3’, ‘4’ and ‘5’.
(4) For specify the first calibration computation, select the function No. ‘6’ and press “SET” key.
‘CAL-1’ display flashes during computation and the density at the reference temperature is
displayed after computation.
Confirm that the density value is almost the same as that of measured at (2).
(5) Before carrying out the second calibration, change the density of the measuring solution in
the sampling unit. Perform the operations of (1) to (4). In the operation corresponding to (3),
input the data to function No. ‘7’, ‘8’ and ‘9’. In the operation corresponding to (4), use the
function No. ‘A’ to specify calibration computation.
5th Edition : Dec. 11, 2015-00