Honeywell SPM, Техническое руководство

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SPM Single Point Monitor
SPM Technical Handbook 5-2
5.1 AccuPulse Dilution System
The heart of the AccuPulse Dilution System is a Teflon
3-way solenoid valve with millisecond speed of response.
The incoming sample gas is drawn through the normally
closed port, a diluent source is drawn through the
normally open port, and the diluted sample is available
at the common port for sampling by the SPM.
The AccuPulse system operates on a gas dilution ratio
which causes the SPM to analyze only a fraction of
the actual gas concentration. The instrument software
contains a multiplier which corrects for this dilution,
and allows the front panel display to report the proper
concentration of the gas being admitted through the
sample tube. The dilution ratio is factory set.
The alarm levels are factory set in accordance with the
calibration of the instrument and typically correspond to
1/2 TLV and TLV, (with both values being multiplied by
the dilution factor).
5.1.1 AccuPulse Installation
Attach 1/8” I.D. x 1/4” O.D. Teflon sample tube to the
sample inlet fitting (15). Sample line lengths greater
than 10 feet are not recommended with this option due
to increased sample transport times. See
Section 4.10
for more information on sample line length.
The sample gas must be at atmospheric pressure to
ensure proper operation of the dilution system. The
fitting marked DILUENT INLET can be left vacant if the
SPM is located in an atmosphere which contains clean
air. If this is not possible, a source of clean air must be
supplied through this fitting at atmospheric temperature
and pressure. Sample stream humidity requirements
must be maintained.
5.2 Z-Purge System Option
The SPM fitted with the Z-Purge option is housed in a
rugged, NEMA 4X fiberglass enclosure. [See Z-Purge
enclosure illustration with accompanying legend (
page
5-3 ) for parts and controls.] The enclosure is designed
to fully utilize the monitoring capability of your SPM
detector while allowing maximum flexibility for mounting
accessories and maintaining proper instrument
operation. It has a fully gasketed seal and a large view-
through front window for easy observation of monitoring
activity. The swing-open door allows access for routine
maintenance. The fiberglass construction withstands
harsh environmental conditions, surface impact, and
corrosive atmospheres.
Caution
Before installing the Z-Purge enclosure or
before starting to connect alarms, make sure you
understand the correct way to disassemble the
enclosure. See Section 5.2.5 for instructions.
The SPM purge enclosure contains all the equipment
necessary for air purging including override switch
(55), explosion proof switch (56), pressure gauge
(54), pressure relief valve (58), inlet regulator (50) and
bulkhead fittings. When closed and purged, the safe,
trouble-free environment insures optimum equipment
performance.
5.2.1 Purge Installation
Sample line requirements for Z-Purge systems are the
same as conventional SPM monitors. See
Sections
2.3 and 4.10 .
Proper venting requires minimal pressure drop at fittings
labeled “PRESSURE RELIEF,” “PURGE OUTLET” and
“ATMOSPHERIC REFERENCE.” Do not attach tubing,