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 temperature effect of flue gases, maintain the
cell temperature in the probe at 843 degrees C 1,550 degrees Fby
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 a.c. electric motor drive. Chart shall be 300 mm
12 inch diameter and rotate once every 24 hours. 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 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.]
f.
A smoke density [indicator] [recorder] of the [density limit]
[continuous density] type with a scale calibrated in Ringlemann
units. Indicating and recording systems shall include circuits
for the audible warning of the maximum smoke density-limit. A
vibrating electric horn shall be supplied to sound the audible
signal. Otherwise the smoke density [indicator] [recorder] shall
conform to MIL-M-29190.
[g.
The annunciator shall be of the solid state type and shall
annunciate safety interlock and limit switch shut-downs, including
flame failure, high and low water, high steam pressure, [high gas
pressure,] [low gas pressure,] [high oil pressure,] [low oil
pressure,] [low atomizing steam pressure,] [draft fan failure,]
[high and low temperature,] [and] [_____]. Annunciator shall
include at least [two] [_____] spare points and audible alarms for
at least high and low water conditions. Annunciator shall not
require special or additional devices which could affect the
sensitivity of the boiler limit switches. Annunciator shall
provide means to indicate the first limit or off-limit condition
causing burner shutdown and to sound an alarm. Annunciator shall
have a test button and a feature capability to store information
on additional causes of burner shutdown. Subsequent causes of
burner shutdown will be indicated after the operator acknowledges
the first burner shutdown. A dust tight enclosure shall be
provided.]
SECTION 15517N
Page 16
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