Instruction Manual MM850481 ed. 03a
15
CAUTION
I
F A SINGLE TUBE GAS SAMPLING PROBE IS USED FOR
P
RESSURE
/
DRAFT MEASUREMENTS
,
BE SURE THAT IT IS CLEAN AND DRY BEFORE
CONNECTION TO THE PRESSURE INPUT
.
CAUTION
A +300
H
P
A
(
OR
–300
H
P
A
)
OVER
-
PRESSURE CAN PERMANENTLY DAMAGE THE PRESSURE SENSOR
.
4.2.3
Smoke index measurement
This method consists of taking a gas sample from the center of the gas pipe behind the heat exchanger and crossing it
through a special filter paper.
The color of the spot on the filter is compared with a graduated (from 0 to 9) reference scale and it is called “smoke index”.
You can type in the instrument up to 3 smoke index values; the analyzer calculate the average value and can print these
values on the report.
Normative and laws about the air pollution, describe the procedure: DIN51402, 2116, 2117 and 2297 VDI directives, ASTM D
2156-63 T, etc.
4.2.3.1
Measuring instruments (option)
1.
Smoke pump
: it should suck 5.75 litres
r
0.25 l (normalized to 0°C, 760mmHg) through a 1 cm
2
filter.
2.
Smoke index reference table
: it is a grey scale sheet with 10 different areas numbered from 0 to 9. The number 0
corresponds to a 85%
r
2.5% reflection. Every area reflects 10% less than the previous one. The scale is used to
compare the scale with the paper filter and to calculate the smoke index.
3.
Paper filter
: When it is clean it has a reflection corresponding to the 0 scale index. It also has 3 litres per cm
2
a minute
(normalized to 0°C, 760mmHg) with a 200/800 mmwc resistance to the air flux.
4.2.4 Other
measurements
The analyzer has an auxiliary input for special probes connections. Available probes are: ambient CO monitoring, and natural
gas monitoring probes.
An optional operative mode is the leakage pipe test to check gas network tightness using pressure decay method at
programmable interval time.
