biosystems PhD Lite, Reference Manual

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6. Note the readings. Oxygen readings are
considered accurate when the display is within
±0.5%/volume of the expected concentration as
given on the calibration gas cylinder. LEL and toxic
readings are considered accurate when they are
between 90%* and 120% of the expected value as
given on the calibration gas cylinder.
* The Canadian Standards Association (CSA)
requires the instrument to undergo calibration when
the displayed value during a bump test fails to fall
between 100% and 120% of the expected value for
the gas.
Note: If gas concentration readings are off by more
than 10 percent higher or lower than the expected
values during a functional (bump) test, the
instrument must be adjusted using the "span"
calibration procedures discussed in section 4.5.2
before further use.
Always check the expiration
date on calibration gas cylinder(s) prior to use.
Expired calibration gas can lead to inaccurate and
potentially dangerous readings.
4.7 The Calibration Menu
The Calibration Menu is an immediate subdirectory of
the Main Menu and provides access to all calibration
functions and controls.
4.7.1 Entering the Calibration Menu
To enter the Calibration Menu:
1. Turn the instrument on and wait until gas readings
appear.
2. Press the MODE button until the information screen
is displayed.
01:15 15:08
3.9V 71F
MENU
3. At the INFORMATION screen hold down the left
navigation arrow for 3 seconds or until EXIT
appears and is highlighted.
01:15 15:08
EXIT
3.9V 71F
MENU
4. Press the down navigation arrow once to highlight
MENU and press the MODE button. The Main
Menu will then be displayed.
ALARMS CALIBRATION
OPTIONS SCREEN
VIEW TIME
EXIT
5. Use the navigation arrows to highlight
CALIBRATION and press the MODE button. The
calibration menu will then be displayed.
FRESH_AIR SPAN_CAL
GAS_VALUES REMIND
IQ LINK
EXIT
CAL LOCK
4.7.2 Gas values
Calibration gas concentration values may be viewed
and adjusted through the gas values screen.
To change calibration gas values:
1. Enter the Calibration Menu as described above in
section 4.7.1.
FRESH_AIR SPAN_CAL
GAS_VALUES REMIND
IQ LINK EXIT
CAL LOCK
2. Use the navigation arrows to highlight GAS
VALUES and press the MODE button.
CALIBRATION GAS
LEL 50.0%
EXIT
Calibration values shown in the
calibration value table must match those appearing
on the calibration gas cylinder(s) that will be used to
calibrate the PhD Lite. Non-matching calibration
gas and calibration gas value settings will lead to
inaccurate and potentially dangerous readings.
3. Use the right and left navigation arrows to scroll
through the available calibration gas settings.
CALIBRATION GAS
LEL 50.0%
EXIT
→
CALIBRATION GAS
CO 50.0ppm
EXIT
4. Once the appropriate sensor is reached, use the up
and down navigation arrows to modify the gas
setting.
CALIBRATION GAS
CO 50.0ppm
EXIT
↓
CALIBRATION GAS
CO 49.9ppm
EXIT
5. Once the concentration matches the value listed on
the calibration gas cylinder(s), press the MODE
button.
Save Changes?
YES NO CANCEL
6. Press the MODE button with YES highlighted to
save the new settings.
Cal Gas Values
Saved
4.7.2.1 Changing the combustible gas readout
from LEL to CH
4
The PhD Lite may be configured to show combustible
gas readings in terms of percent of LEL (Lower