biosystems PhD Lite, Reference Manual

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TWA CO H
2
S
1:45 0 0
TWA screen in Technician Mode.
Note: It is not possible to calculate a toxic gas TWA
reading until the PhD Lite has been operating for 15
minutes. For the first 15 minutes after start-up, the
TWA screen will show an “X” in place of the
calculation. After 15 minutes, the TWA calculation
will be shown.
Appendix A discusses Permissible Exposure Limit
alarm calculations in greater detail.
3.4.2.5.3 Average readings
Average readings are calculated by taking the sum of
exposure to a particular toxic gas in the current
operating session in terms of parts-per-million-hours
and dividing by the amount of time that has passed in
the current operating session.
AVERAGE O
2
LEL
20.9 0
Average readings screen (O
2
& LEL) in Technician Mode.
3.4.2.6 Changing the user mode
1. Enter the Options Menu as discussed in section
3.4.1 and use the navigation arrows to highlight
USER_MODE.
USER_MODE SEC_BEEP
PASSCODE LANGUAGE
DECIMAL T_UNITS
EXIT
2. Press the MODE button. The up and down arrows
may then be used to toggle between operating
modes.
Operating Mode
Text Only
EXIT
↑↓
Operating Mode
Basic
EXIT
↑↓
Operating Mode
Basic/Peak
EXIT
↑↓
Operating Mode
Technician
EXIT
3. Once the preferred operating mode is displayed,
press the MODE button.
Save Changes?
YES NO CANCEL
4. Press the MODE button with YES highlighted to
save the new operating mode.
Note: Changing modes or otherwise
reprogramming the instrument is reserved for
authorized employees.
3.4.3 Security beep
The security beep is an audible alarm that “beeps” on a
regular basis while the PhD Lite is in normal operation.
The beep serves as a reminder that the instrument is
turned on.
3.4.3.1 Adjusting the security beep
1. Enter the Options Menu as discussed in section
3.7.1
USER_MODE
SEC_BEEP
PASSCODE LANGUAGE
DECIMAL T_UNITS
EXIT
2. From the Options Menu use the navigation arrows
to highlight SEC_BEEP. To enable or disable the
security beep, use the right and left navigation
arrows to highlight OFF (or ON). The up and down
navigation arrows may then be used to toggle
between security beep on and security beep off.
Security Beep
Off
EXIT
↓↑
Security Beep
On 01m 00s
EXIT
3. The interval setting will appear when the security
beep is turned ON (as above). Use the right and
left navigation arrows to highlight the interval if it
requires adjustment. Then use the up and down
navigation keys to adjust the interval.
Security Beep
On 01 m 00s
EXIT
↑
Security Beep
On 02 m 00s
EXIT
4. Once the desired interval is reached use the right
and left navigation arrows to highlight EXIT.
Security Beep
On 02m 00s
EXIT
5. Press the MODE button to enter the new setting.
Save Changes?
YES NO CANCEL
6. Press the MODE button with YES highlighted to
save the new setting.