User's Manual

05206H DCN5910 41
5.0 ALARMS AND CAUTIONS
A functional block diagram of the analyzer is shown in Figure 5-1.
5.1 ALARM
During initial warm up the internal Zero/Span factory option may exhibit a “Block
Temperature” warning. This can be cleared once the block temperature stabilizes
at 50 degrees Celsius. The block temperature is the actual temperature of the IZS
block manifold inside the M501 NH
3
, converter. If the block temperature warning
exhibits a negative number such as (-37), then the umbilical cord is probably not
attached or the Thermistor has become disconnected.
5.2 CAUTION
Be aware that the ammonia converter operates at 825 degrees Celsius. Do not
flow highly flammable gases through the M201E analyzer. When the analyzer is
not in use, it is advisable to turn off the M501 NH
3
,. If the converter hasn’t been
powered for an extended period of time it is recommend that the analyzer be
operated overnight prior to use.
Before spanning the analyzer it is good practice to observe the NORM PMT
signal. Its value should be equal to twice the concentration of the delivered span
gas. A common error made during calibration is to span the analyzer with either
too low a gas concentration or an incorrect value entered into the CONC menu
for TNx and NOx. Commonly this will cause a slope value much greater than
one.
Note: Always zero then span as a basic rule of thumb.