RKI Instruments RI-215A - Manual (Page 22)

22 • Calibration RI-215A Operator’s Manual
Calibration
This section describes how to calibrate the RI-215A. It includes procedures to prepare for
calibration, set the zero reading, set the response (span) reading, and return to normal
operation.
WARNING: The RI-215A is not an active gas monitoring device during the calibration
procedure.
Preparing for Calibration
Turn on the power to the RI-215A, and let the unit warm up for at least 30 minutes.
Connect the sample tubing from your calibration kit to the hose barb on the fixed flow
regulator. The fixed flow regulator should be a 0.5 LPM (liters per minute) regulator.
NOTE: Do not screw the regulator onto the calibration cylinder at this time.
Setting the Zero Reading
1. Locate the function switches on the bottom of the unit.
2. Press and hold the MODE switch (M) for three seconds to enter Maintenance Mode.
The display will show “1” to indicate Zero Adjustment Mode.
3. Press the SET switch (S) to enter Zero Adjustment Mode. The display will show a
reading with a flashing decimal point before the first and third digits, for example
“. 1.5“.
4. Remove the rubber cap covering the calibration gas inlet port at the bottom of the
unit.
5. Insert the calibration tubing into the gas inlet opening at the bottom of the RI-215A
and push the tubing over the calibration fitting.
6. Screw a 100% nitrogen calibration cylinder (a CO
2
-free source) into the regulator.
7. Allow the gas to flow for one minute or until the gas reading stabilizes.
8. Press the SET switch (S) and the unit will adjust the reading to zero. Be careful not to
breath onto the RI-215A since the CO
2
in your breath may affect the reading.
9. Press the SET switch (S) and the display will again show a “1”.
10. Unscrew the regulator from the nitrogen cylinder.
11. To proceed with setting the span, press the Up ( ∆) switch to display “2” which
indicates Span Adjustment Mode and continue with the next section, Setting the
Response Reading.
12. To return to normal operation, skip to Returning to Normal Operation below.
Setting the Response Reading
1. With “2” showing in the display, press the SET switch (S) to enter Span Adjustment
Mode. The display will show the current gas reading with a flashing decimal point
before the second and third digits, for example “.6.50“.
2. Press the SET switch (S) again and the reading will start to flash.