User Guide

• Check the voltage setting (110 or 220 VAC) on the back of the
instrument. Ensure that it is set to the correct voltage. If the
pointer is not aligned to the local voltage, turn the selector to
point to the correct voltage.
• Perform a sensor regeneration by following these steps:
 Connect the line cord between the connector on the back of the 631-X and an AC power
outlet.
 Press the ON switch and then press the REGEN button.
 The instrument will begin a 10 minute regeneration cycle, indicated by .H.H.H flashing
on the display. Do not interrupt this cycle. For a complete description of this
process, see page 12.
 If any error message, such as .P.P.P, appears on the display, see the “Troubleshooting”
section beginning on page 24.
• When regeneration is complete, zero the sensor by pressing the ZERO button and turning
the zero adjust screw, located under the handle, until the display reads 0.
• The instrument is now ready to sample.
• To ensure the input to the instrument contains no hydrogen sulfide or mercaptans, use a
Zero Air Filter, AZI P/N Z2600 3905. The Zero Air Filter cleans the air sample and should
produce sample readings of less than 0.003 mg/m
3
. Therefore, use the filter to:
 Equilibrate the instrument to temperatures that are higher or lower than the instrument.
Sample with filter installed until the reading is below 0.003 mg/m
3
.
 Identify contamination within the unit.
 Confirm the presence of hydrogen sulfide when readings are elevated. Install filter and
verify that the readings go down with filter installed.
• When the instrument measures hydrogen sulfide, the zero display will be replaced with H.
CAUTION
Do not adjust the ZERO after the instrument has measured hydrogen sulfide
or before the next regeneration. (Occasionally the display may drop to .L.L.L
(indicating low) between the initial zeroing and the first sample. It is OK to
readjust the ZERO if the instrument has not measured hydrogen sulfide.)
• The instrument is designed for ambient air monitoring. DO NOT allow the probe or the
instrument’s intake to be exposed to any liquid.
• The instrument is not explosion proof.
• Press the SAMPLE button to start a 10 second sampling cycle.
• Perform sensor regeneration after each day’s testing.
• Perform another sensor regeneration and re-zero the instrument before each day’s use.
• Perform sensor regeneration after 30 days of storage or inactivity.
Call AZI Customer Service, at [phone] from the United States and Canada or (602)
470-1414 if you have any questions. If you prefer, you may send e-mail to [e-mail]
AZI Customer Service 800-528-7411 or 602-470-1414 Page 5 of 50