Emerson 51-DO-03, 51-DO-04 Stabilizing . . . Wait, Calibrating the Sensor in AIR

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MODEL DO-03/04

SECTION 7.0

 

CALIBRATION - DISSOLVED OXYGEN

7.3CALIBRATING THE SENSOR IN AIR

1.Remove the sensor from the process liquid. Use a soft tissue and a stream of water from a wash bottle to clean the membrane. Blot dry. The membrane must be dry during air calibration.

2.Pour some water in a beaker and suspend the sensor with the membrane about 0.5 inch (1 cm) above the water surface. To avoid drift caused by temperature changes, keep the sensor out of the direct sun.

3.Monitor the dissolved oxygen reading and the temperature. Once readings have stopped drifting, begin the calibration. It may take 5 - 10 minutes for the sensor reading in air to stabilize. Stabilization time may be even longer if the process temperature is appreciably different from the air temperature. For an accurate calibration, temperature measured by the sensor must be stable.

Calibrate main sensor Zero main sensor Adjust temperature

ExitEnter

4.From the main display, press any key to obtain the main menu. With the cursor on “Calibrate,” press Enter (F4).

NOTE

If Hold was enabled in Section 5.5, the hold screen will appear. To activate hold, refer to Section 5.5, step 9.

Calibrate in air Calibrate in process Barometric pressure

Press Enter (F4). The screen shown in step 5 appears.

5. Press Enter (F4) to select “Calibrate in air.”

ExitEnter

Bar press : 760 mmHg

Temperature: 25.0°C Press F3 to air cal

Abort Cont

6.This screen shows the barometric pressure and temperature that will be used for the calibration. If the barometric pressure or temperature is incorrect, press Abort (F1). Refer to Section 7.5 for the pressure cali- bration procedure. Refer to Section 6.2 for the temperature calibration procedure.

8.20ppm

Stabilizing . . . Wait

Abort Cont

NOTE

The barometric pressure sensor is inside the controller enclosure. When cable glands are in place and the front panel is tightly closed, the enclosure is moderately airtight. Therefore, as the controller heats or cools, the pressure of the air trapped inside the enclosure may be different from ambient. Opening the front panel will equal- ize the pressure.

7.Press Cont (F3). “Wait” flashes until the sensor is stabilized. Once air calibration is complete, the message “Air calibration done” appears. The display will show the equilibrium solubility of atmospheric oxygen in water at the prevailing temperature and pressure.

procedure continued on next page . . .

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Contents Model DO-03/04 Dissolved Oxygen Measurement System with Air Blast CleanerEssential Instructions Page Section Title Model DO-03/04 Measuring SystemList of Tables 10.011.0 List of Figures Section TitleIii Features and Benefits Section SpecificationsOutput Accuracy ± 0.05 mA PowerRepeatability ±0.05 ppm 25C RFI/EMI EN-61326Maximum continuous pressure 50 psig 446 kPa abs Maximum distance between compressor and sensorMaterials of Construction Analyzer dimensions Enclosure dimensions Power required selection Description9240048-00 Tag, stainless steel, specify marking Model or part number Description Section InstallationInstallation Unpacking and InspectionInstalling the air compressor enclosure Installing the handrail mounting assemblyAssembling the pipe and pipe clamp Installing the sensor in the washer head assembly Attaching the pipe boom to the handrail mounting assemblyAssembling the washer head and pipe boom Attaching the air compressor enclosure to the handrail Installing the sensor in the washer head assembly Section Wiring POWER, ALARM, and Output WiringGeneral 454EPH02 Section Section Sensor Wiring Wiring the Oxygen SensorGeneral KEY Functions and Control Alarm StatusSection Display and Operation DisplayMenu Tree for the 54eA Analyzer Section Software ConfigurationOn following Main Menu Calibrate See Diagnostic Variable see Choices Factory Settings Setpoints Program Settings ListChoices Factory Settings Configure Choices Factory Settings Alarm 3 setpoint Alarm setpointsAlarm 1 setpoint Alarm 2 setpointRanging the Outputs MA 0.00 ppm 20 mA 20.00 ppm Output 1 12.00 mATest alarm 1 Open Simulated testsTest output Meas units ppm Outputs AlarmsDisplay Measure OxygenDisplay contrast Timeout On Temp units C Output 1 mA Output 2 mALanguage English Display left Display right Out Outputs Output 1 controlOutput Measurement Output 1 Setup Output 1 ControlRange 4-20 mA Dampen 0 sec Hold Last Value Changing Alarm Parameters ConfigureAlarm 1 control Alarm 1 setup Alarm 2 controlActivate Process Alarm 1 controlAlarm 1 setup Alarm LowAlarm 4 setup Alarm FaultFeed limit Disable Timeout 3600 secInterval timer setup Alarm 4 setup Feed limit timerInterval timer Timer Disable Timer Time activated Interval 24.0 hrTemp comp Manual Temp units C Temperature Compensation and Temperature UnitsTemp comp Auto Temp units CNoise Reduction 60 HzBar meas Auto Bar units mm HgBarometric Pressure Salinity 0.0 o/oo Main sensor calSecurity Noise rejection Main sensor cal SecurityAnalyzer Mode Priority Condition DefinitionsAction Definitions Introduction Section Calibration Temperature Temperature Calibration Adjust temp + 025.1 CSensor Current as a Function Dissolved Oxygen Concentration Section Calibration Dissolved OxygenZeroing the Sensor Sensor must be in zero solutionCalibrating the Sensor in AIR Stabilizing . . . WaitSection Calibrating the Sensor Against a Standard Instrument Calibrate 8.32 ppmCalibrating Barometric Pressure Zero main sensor Adjust temperatureCalibrate main sensor StandardizeTrimming the Outputs Section Calibration Current OutputsReplacing electrolyte solution and membrane Section MaintenanceReplacement Parts Cleaning the membraneSection Spare Parts Power FuseAIR Blast Sensor Washer Replacement Parts Location Part Number DescriptionOverview Section TroubleshootingTroubleshooting When a Fault Message is Showing Fault message Explanation See SectionSense line open Temperature error low or highHigh input current Check sensor zeroTroubleshooting When no Fault Message is Showing Oxygen Problem See SectionZero current is too high Possible error warning during in-process calibration Zero reading Is unstableBarometric pressure reading is too high or too low Oxygen readings are too low Process readings are erraticReadings drift Sensor does not respond to changes in oxygen levelSensor Polarizing Voltage Resistance Expected current Troubleshooting not Related to Measurement ProblemsProblem Action Simulating Inputs Dissolved OxygenSimulating temperature Simulating TemperatureGeneral Section Return of MaterialSensor or Circuit Board only Return of Materials RequestWarranty Specifications subject to change without notice
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