UNITED Nitrogen Pac SC-W, Установка, наладка, обслуживание

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2. N
2
ANALYZER FEATURES AND FUNCTIONS
LCD Display : A 3-digit display provides a direct readout of nitrogen concentration in the range of 0 -
99.9%. The display is blank when the N
2
Analyzer enters its sleep (power off) mode. The N
2
Analyzer
will automatically enter the sleep mode after 2 minutes from the last time the analyzer was energized.
You can manually turn off the analyzer by pressing the on/off switch.
ON Button/Auto OFF : Use this button to turn the N
2
Analyzer on or off. When the N
2
Analyzer is in
the Sleep (power off) mode, the LCD display is blank. When the ON button is pressed once, the
analyzer will display the nitrogen concentration for 2 minutes. Pressing the ON button during this 2
minute "window" will prolong the ON period to 2 minutes from the most recent time that the button
was pressed.
Calibration Button : This button is used to place the analyzer into enter calibration mode. Holding the
button for more than three seconds will place the analyzer into enter calibration mode.
Over-Range Indicator : The appearance of a decimal point after the first digit means that the N
2
Analyzer is reading in excess of 99.9%.
Example: 0.0.0 = 100% 0.0.1 = 101% ; 0.0.2 = 102%. The displayed value is not valid. Re-calibrate
the analyzer and repeat the measurement.
Oxygen Sensor : This is used to measure oxygen concentration in sample gas.
Sample Inlet Connection : This is the port at which the analyzer is connected to determine nitrogen
concentration.
3. PRINCIPLE OF OPERATION
The instrument display corresponds directly to the oxygen sensor. The oxygen diffuses through the
membrane and an electrical current is generated that is proportional to the partial pressure of oxygen
in the gas sample. The oxygen percentage is subtracted from 100, with the remainder being
displayed as percent nitrogen. The sensor has a minimal response to gases other than oxygen.
4. PRE-USE CHECKOUT/CALIBRATION:
Follow these steps before using the N
2
analyzer.
4.1. Prior to turning on the analyzer, a protective film covering the threaded sensor face must be
removed. After removing the film, wait approximately 20 minutes for the sensor to reach
equilibrium.
4.2. Pre-assembly, if required.
- Thread the barbed adapter onto the oxygen sensor.
- Connect the clear tubing to the barbed adapter.
4.3. Using the "ON/OFF" button, make sure
the unit is in the power "ON” mode.
4.4.
Press and hold the Calibration button for 3 seconds until the display reads “CAL”. This will
calibrate the N
2
analyzer to room air. Thereafter, we recommend calibration on a weekly basis.
A new calibration is required when:
- The measured N
2
percentage in 79.1% N
2
(normal air) is above 80.1%.
- The measured N2 percentage in 79.1% N
2
(normal air) is below 78.1%.
If you are unsure about the displayed N
2
percentage, see Factors Influencing Accurate Readings.
4.5. The N
2
analyzer is now ready for use.