Sample cell windows should be cleaned when the optical signal strength (CO2 and/or H2O) diminishes to 80%. A conservative approach is to change the blue filter (Campbell Scientific pn 31210, Parker pn 9922-05-DQ) at the same time that the windows are cleaned. The inside of the vortex body may require cleaning with a lint-free wipe and clean water or isopropyl alcohol at the time of the filter change.
An increased magnitude of cell-pressure drop may also indicate a clogged filter. The table below shows some example cell pressure readings in our laboratory with the CLIP-ON vortex. Readings with the “100% clogged” filters were made by physically plugging the bypass tubing. Note: These pressures do not apply to the new standard vortex intake, which has more pressure drop and requires a different filter kit (Campbell Scientific pn 32203) that consists of a filter with pre-installed Swagelok nuts.
EC155 CLIP-ON Vortex intake (readings in lab @23 deg C, 87.9 kPa)
| Pump Flow (liter per minute) | Blue Filter (dirty air bypass) | Absolute Cell Pressure (kPa) | Differential Pressure (kPa) |
|
0.0 (pump off) |
87.9 |
0.0 |
|
|
7.0 |
New Filter |
85.0 |
-2.9 |
|
7.0 |
100% Clogged (zero bypass flow) |
83.8 |
-4.2 |
|
8.0 |
New Filter |
84.2 |
-3.7 |
|
8.0 |
1100% Clogged (zero bypass flow) |
82.8 |
-5.1 |