(3) Analyzer output and recorder input shall be compatible.
Provide, connect, and place in proper operation necessary
transducers. Follow special instructions relating to electrical
transmission between analyzer and recorder as to the application
of shielded wiring in conduit.
(4) Check the system with two calibrating gases as follows: (a)
100 percent nitrogen, and (b) 3.5 percent oxygen and remainder
nitrogen.]
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NOTE: These instruments are not normally required
on boilers under 2930 kW 10,000,000 Btu/h.
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[c.
Direct Probe In-Situ Type: Oxygen analyzer shall be the direct
probe type utilizing an in-situ zirconium sensing element. Insert
element directly in the process flue gas stream and in direct
contact with process gasses. Sensing element shall be contained
within a protective shield mounted to the duct work by means of an
adapter plate, all furnished by the manufacturer. Analyzer shall
be equipped with a facility to allow daily automatic calibration
check without removing the analyzer from the process. That is,
sample gases may be injected directly on the sensing element while
the analyzer is in the process. In order to eliminate the
temperature effect of the flue gases, maintain the cell
temperature in the probe at 843 degrees C 1,550 degrees F by means
of an externally mounted temperature controller equipped with cold
junction compensation and coupled to the probe with at least 6
meters 20 feet of flexible cable. Analyzer shall be FM P7825
approved and certified for "in-stack" analysis technique. Output
signal range shall be 4 to 20 milliamps and shall represent 0.25
percent to 25 percent oxygen as a logarithmic function, 0.1
percent to 10 percent oxygen as a logarithmic function, or zero
percent to 10 percent as a linear function. [Circular chart
recorder shall consist of a two-pen recording control mechanism
having 110 volt ac electric motor drive. Chart shall be 300 mm 12
inch diameter and have 24-hour revolution. Output control signal
will be 20 to 103 kPa (gage) 3 to 15 psig pneumatic. Sufficient
blank charts and four ink cartridges per pen for 400 days
operation shall be provided. Recorder shall have a dual 30
degrees strip indicator. Strip indicator and chart paper scale
shall be logarithmic or linear and consistent with the analyzer
signal conditioning.] [Strip chart recorder shall consist of a two
pen solid state electronic recording/controlling mechanism. Strip
chart shall be 100 mm 4 inches wide and shall be driven at a speed
of 19 mm per hour 3/4 inch per hour. Recording/controlling
mechanism will operate on 110 volt ac power. Recorder shall be
furnished with twelve usable 24-hour logarithmic or linear charts
consistent with the analyzer signal conditioning. Inking system
shall be a breakaway inking system with replaceable fiber tip pens
and 12 ink cartridges. Strip chart recorder/controller shall have
vertical scale and horizontal driven chart. Output control signal
will be 4 to 20 milliamps dc.] Flue gas temperature scale shall be
149 to 427 degrees C 300 to 800 degrees F. Entire system
response shall be not more than 3 seconds.]
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NOTE: These instruments are not normally required
SECTION 15516N
Page 12
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