E Instruments E4500, Руководство по эксплуатации и техническому обслуживанию

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7.4.1 Gas sampling probe
The gas sampling probe is made up of an INOX steel tube with a plastic hand grip and an internal K-type
thermocouple (Ni-NiCr) for measuring the gas temperature up to 1470
° F ( 800°C). Flue gas temperature is
measured by means of a thermocouple inserted in the tip of the probe.
The thermocouple is connected to the instrument via a compensated cable housed in a special seating in the
rubber hose of the sample probe. The cold junction is compensated by a Pt 100 resistance thermometer which
measures the temperature at the thermocouple connector. The type K thermocouple (nickel/nickel chromium)
permits continuous measurements up to 800°C. If special-purpose probes are used, the instrument is able to
measure temperatures as high as 2190
° F (1200°C).
A Pt 100 resistance thermometer located inside the instrument measures the internal temperature; this sensor is
also used to measure the ambient temperature.
Should the user want to measure the combustion air temperature directly in the intake duct, the optional remote
Tc-K sensor must be used - this measurement is recommended for more precise calculation of plant efficiency.
This type of probe is available with a rigid tip with different lengths:
300mm:
rigid tip
750mm: rigid tip
1000mm: rigid tip
7.4.2 Condensate trap and fine dust filter
The sample gas to be analyzed shall reach the measurement sensors after being properly dehumidified and
purified from the residual combustion products. To this purpose, a condensate trap is used, which consists of a
transparent polycarbonate cylinder placed along the rubber hose of the sampling probe. Its purpose is to
decrease the air speed so that the heavier fine dust particles can precipitate and the vapor in the combustion
gases can condense.
The condensate trap must be always kept in the vertical position in order to prevent condensate from
touching the measurement sensors. This is also the reason why it is important to periodically drain the
trap at the end of each test (see chapter 'MAINTENANCE').
A replaceable low-porosity line filter is placed after the condensate trap aimed at removing the solid particles from
the gases. It is recommended to replace the filter whenever visibly dirty (see chapter 'MAINTENANCE').
7.4.3 Connecting the gas sampling probe and water-trap assembly
As shown in section 7.4 the gas sampling probe must be connected to the device as follows:
•
The polarized male connector of the thermocouple must be connected to the lower part of the device in the T1
socket. The improper insertion of the same is not possible thanks to the different lengths of the tips.
•
The shorter tube of the probe must be inserted in the condensation trap with ant-dust filter (see section 7.4.2).
•
The male connector of the filter assembly must be connected to the central female connector of the device
marked with "
IN ".
•
The longer tube of the probe, which ends with a male connector, must be connected to the positive pressure
input of the device marked with the letter "P+".
The different diameter of the connectors does not allow improper connections: this avoids damage to the device.
7.4.4
Connecting the TcK probe
Using the same input as for the K thermocouple " T1 " (the same used for gas temperature), it is possible to
measure the water delivery and return temperature by connecting some special probes . If temperature is taken
on the pipe, it is suggested to use arc probes with a suitable diameter.
KEEP THE CONDENSATE TRAP IN THE VERTICAL POSITION DURING THE ANALYSIS; A
WRONG POSITION MAY CAUSE CONDENSATION IN THE INSTRUMENT AND DAMAGE
THE SENSORS.
AFTER EACH ANALYSIS, CHECK FOR ANY PRESENCE OF WATER IN THE CONDENSATE
COLLECTION BOWL AND REMOVE IT, IF ANY. PUT THE PROBE BACK IN THE CASE ONLY AFTER YOU
HAVE ELIMINATED CONDENSATE FROM THE TUBE AND THE EXPANSION TANK (SEE CHAPTER
'MAINTENANCE').
REPLACE THE FINE DUST FILTER IF IT IS VISIBLY DIRTY OR WET (SEE CHAPTER 'MAINTENANCE').
DO NOT PERFORM ANY MEASUREMENT WHEN THE FILTER IS REMOVED OR DIRTY IN ORDER TO
AVOID ANY RISK OF IRREVERSIBLE DAMAGES TO SENSORS AND ANALYZER ITSELF.