Instrument Damage - Super Systems DP 2000 Operation Manual

DP2000 Portable Dew Point Analyzer Operations Manual
The optimum flow rate of the sample gas
should be between 1.5 and 2.0 cubic feet per
hour (CFH) (Figure 7), although a flow rate as
low as 1.0 CFH is acceptable. If the unit is
reading less than 1.0 CFH, verify that there are
no obstructions to the flow such as a clogged
sample line or a poorly adjusted knob on the
DP2000's flow meter. If these conditions do
Figure 7
not exist, the unit may need to be returned to
SSI for replacement of the pump. The pump's life is dependent upon how
frequently it is used as well as the cleanliness of the sample gas. Insufficient
filtration will significantly reduce the operating life of the pump.
Heat Treat Furnace Sampling:
A gas sample may be extracted from a process
using the built-in pump. The sample tube from which the sample is taken out of
the furnace should extend into the furnace past the HOT face of the refractory.
For accurate results, a designated sample port should be used to extract the
sample. SSI offers a sample port assembly (part number 20263) which is ideal
for this purpose. If a designated sample port is not available, then a clean "burn-
off" port on an SSi Gold Probe, an industry leading oxygen sensor for
atmosphere control, can be used. Readings taken from the burn-off port on a
probe may be artificially high due to the presence of soot in the probe sheath.
Endothermic Generator Sampling:
For applications under pressure, the pump
should be switched off and the flow controlled by the small restriction valve on
the flow meter. A flow rate between 1.5 and 2.0 CFH is ideal. The sample should
be taken from the endothermic gas manifold after the gas has been cooled.
NOTE: Allow the sample port to blow out any soot and / or water before
connecting the sample tube. Failure to do so will result in inaccurate readings
and expose the sensor to potential damage.

INSTRUMENT DAMAGE

The two main causes of damage to the DP2000 are the ingestion of soot and
water. Both of these contaminants will cause erroneous readings in the short
term, and cause long-term damage to the sensor and internal components.
Soot / Particulate Contaminants
When taking a sample from a furnace or a generator, care should be taken to
reduce the amount of soot that enters the instrument. The in-line filter will trap
these particles, but cleaning the sample line before attaching the DP2000 will
Super Systems Inc. Page # 8 of 30