Air Quality Instruments
27 Forge Parkway
Franklin, MA
508-520-0430 ph
www.thermofisher.com
02038
508-520-1640 fax
Technical Bulletin
49i Series Cell A/B Test
Models 49i / 49i-PS
Bulletin# SGSQ42012-2
Rev 00/2012
The purpose of this procedure is to provide instrument users an easy to use procedure
to check for solenoid leaks in the Model 49i Ozone Analyzer or 49i-PS Primary Standard
Calibrator.
Leaks in the solenoids can cause an imbalance in concentration readings between cells.
When an imbalance is noticed this test should be performed to help determine the cause
of the imbalance.
This procedure assumes some user familiarity with the instrument menu structure.
If difficulty is encountered navigating the menu, please consult the instrument instruction
manual where a menu structure breakdown is located. It is entitled Flowchart of Menu-
Driven Software and is typically located in the beginning of Chapter 3
– Operation.
1.
Using an external source of ozone generate approximately 0.5 ppm (500
ppb) and introduce to the analyzer or calibrator.
2.
Press the menu button to enter the main menu.
3.
Using the down arrow button, scroll down to the diagnostics menu selection
and press the enter button to display the diagnostics menu selections.
4.
Again using the down arrow button scroll down to Cell A/B O3 and press
enter. The unit will now display the concentration as determined in each cell
individually.
5.
Once the unit has stabilized on the external ozone gas sample, using a
separate piece of paper, manually take 10 successive simultaneous update
readings from Cell A and Cell B. Readings update every 10 seconds. Find the
average of the Cell A readings and the average of the Cell B Readings. The
average readings of Cell A and Cell B should agree /- 3% of each other.
