YOKOGAWA WE440, User Manual

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<4. Analyzer Hardware Configuration and Calibration>
4-2
IM 12Y18A04-01EN 1st Edition : Oct. 04, 2019-00
4.3 Reaction Cell Temperature Calibration
In order to get consistent and repeatable measurements, the method is setup such that the
reaction cell in the WE440 Phosphate Analyzer is heated to a specific set point (25°C). A heater
element located on the back plate of the reaction cell controls the temperature. The temperature
of the reaction cell is measured by a thermistor embedded in the reaction cell body. The
temperature of the cell is displayed on the results screen.
NOTE
Calibration is typically NOT required except in rare cases where the thermistor has been replaced
and the default parameters are not functional.
The WE440 Phosphate Analyzer relies on a PID (Proportional, Integral, Derivative) algorithm
setting to control and maintain the cell at the set point. The following procedure allows for tuning
and calibrating of the thermistor in case it was replaced or required adjustment.
Heater temperature calibration:
MENU → SERVICES → HARDWARE SETUP → CALBRATE THERMISTOR
Press F3 key to RESET thermistor calibration value to FACTORY DEFAULTS.
The operator is asked to read the temperature of the reaction using an external digital
thermometer and enters the value. The unit will make appropriate correction if needed.
Editing the calibration results:
Upon successful completion of temperature calibration, the new calibrated temperature is
available for further editing. From the MAIN MENU, follow the sequence:
MENU → SERVICE → HARDWARE SETUP → EDIT CALIBRATED VALUES
4.4 Pumps Calibration
The WE440 Phosphate Analyzer uses peristaltic pumps to move fluids through the reaction cell.
The pump tubing will require replacement periodically. Please refer to Chapter 8 for details.
The maximum rate of flow of the fluid is dependent on both the inner diameter of the tubing
conveying the fluid and the rpm of the pump. The pumps are used to move the following fluids:
sample, standard, and reagents.
WHEN REPLACING WITH SAME TYPE FACTORY TUBING, USER MAY BYPASS ANY
CALIBRATION AND USE FACTORY DEFAULT VALUES. IF SUBSTITUTE TUBING IS USED,
PUMP CALIBRATION IS REQUIRED TO INSURE ACCURATE DOSING.
4.5 Pumps Calibration Method
From the MAIN MENU, follow the sequence:
MENU → SERVICES → HARDWARE SETUP → CALIBRATE PUMPS
Select the pump to be calibrated. The user is now asked to prime the pump with de-ionized water
and to respond when ready. The pump calibration procedure is aborted if the user fails to confirm
readiness to pump de-ionized water within 90 seconds.
The sequence starts with a priming step to allow fluid to purge the air from the tubing. The user
may respond as soon as ready. The prime step will stop after 60 seconds. The next step prompt
asks the user to be prepared to collect the water in a measuring cylinder. This step must be
allowed to complete and is timed at 60 seconds to allow the user to enter the volume collected in
60 seconds (or 1 minute). If the measured volume amount is not entered within 90 seconds, the
pump calibration procedure is aborted.
Upon successful completion of the pump calibration procedure, the user has the choice to
calibrate the remaining pumps or to edit the calibrated values.