Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 293)

Troubleshooting & Repair Model 9110TH NOx Analyzer
Teledyne Analytical Instruments 273
very large and the dryer’s efficiency is low at first but improves as this cycle reduces the
moisture in the sample gas and settles at a minimum humidity.
Figure 8-11: 9110TH/M Perma Pure ® Dryer
Just like on startup, if the instrument is turned on after having been off for more than 30
minutes, it takes a certain amount of time for the humidity gradient to become large
enough for the Perma Pure
® Dryer to adequately dry the air. In this case, called a cold
start, the O
3
Generator is not turned on for 30 minutes. When rebooting the instrument
within less than 30 minutes of power-down, the generator is turned on immediately.
The Perma Pure ® Dryer used in the 9110TH/M is capable of adequately drying ambient
air to a dew point of ≤ -5˚C (~4000 ppm residual H
2
O) at a flow rate of 1 standard liter
per minute (slpm) or down to ≤ -15˚C (~1600 ppm residual H
2
O) at 0.5 slpm. The
Perma Pure ® Dryer is also capable of removing ammonia from the sample gas up to
concentrations of approximately 1 ppm.