Monitoring Detector Frequencies And Noise; Increasing Lamp Output; Monitoring Lamp Noise - Thermo Scientific 49i Instruction Manual

Preventive Maintenance

Monitoring Detector Frequencies and Noise

Monitoring Detector
Frequencies and

Increasing Lamp Output

Monitoring Lamp Noise

5-4 Model 49i Instruction Manual
The Model 49i measures intensity ratios and not absolute values. Therefore,
a large range of detector frequencies are acceptable for proper operation of
the instrument. The nominal values are 65 to 120 kHz. These frequencies
Noise
can be monitored from the Intensities screen in the Diagnostics menu.
1. Press
2. Use
scroll to Intensities and press
The Intensities screen appears.
Degradation of detector frequencies to below 65 kHz indicates either a dirty
cell or low lamp output. In addition to degrading the measured detector
frequency, dirt in the cells can decompose the ozone and give erroneous
readings. Therefore, the cells should first be cleaned and the frequency
re-measured.
If the frequencies are still low, the lamp output can be increased by using the
Lamp Setting screen in the Service mode. If the frequency cannot be set
above 65 kHz, replace the lamp.
1. Press
2. Use
Lamp Setting and press
The Lamp Setting screen appears.
If the Service Mode is not displayed on the Main Menu, use the
following procedure to display it.
a. At the Main Menu, press
press
The Service Mode screen appears.
b. Press
c. Press
To monitor the lamp noise, display Intensity Check from the Service mode
menu.
to display the Main Menu.
to scroll to Diagnostics, press
to display the Main Menu.
to scroll to Service, press
.
> to scroll to Service Mode > and press
to toggle the Service Mode to ON.
> to return to the Main Menu.
>
.
>
to scroll to Instrument Controls >
Thermo Fisher Scientific
to
to scroll to
.