Chemical and Petroleum Engineering, Vol. 54, Nos. 1–2, May, 2018 (Russian Original Nos. 1–2, Jan.–Feb., 2018)
0009-2355/18/0102-0048 ©2018 Springer Science+Business Media, LLC
Nauchtekh Company, Moscow, Russia; e-mail: email@example.com. Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 1,
pp. 34–38, January, 2018.
PHOTOMETRIC GAS ANALYZER FOR ATMOSPHERIC SO
V. A. Buzanovskii
The design and metrological characteristics of a photometric gas analyzer for atmospheric sulfur dioxide
that is equipped with adsorbing polymer ﬁ lms are considered. It is shown that the device can solve ecological
and health safety issues and has small overall dimensions and power consumption.
Keywords: sulfur dioxide, photometric gas analyzer, metrological characteristics.
Sulfur dioxide (SO
) is used or formed by processes of the chemical, oil-and-gas, and related industrial sectors. The
compound belongs to hazard class 3. The daily maximum allowed concentration (MAC) for atmospheric SO
is 0.05 mg/m
maximum one-time dose, 0.5 mg/m
. The MAC for SO
in workplace air is 10 mg/m
. Therefore, devices are required
to measure the atmospheric SO
concentration. Existing technical facilities are being updated. New gas analyzers based on
novel (previously unapplied) operating principles are being developed.
The goal of the present work was to consider the possible design and metrological characteristics (static gains, mea-
surement sensitivity and absolute uncertainty) of a photometric gas analyzer for atmospheric SO
that was equipped with
adsorbing polymer ﬁ lms. The aforementioned device parameters were analyzed by mathematical simulation.
The device functioned as follows. Radiation from source S (Fig. 1) entered measurement chamber C. The radiation in-
tensity decreased from I
to I on passing through the chamber. Detector D transformed the radiation at the measurement chamber
output into an electrical signal, which ampliﬁ er A formed into gas-analyzer output signal W, which was fed into recorder R.
Two optical windows were positioned opposite each other in the measurement chamber (Fig. 2). Round glass plates
were set into the windows. One side of the plates (contacting the analyzed air) was spin-coated with n-decylmethacrylate
(MA)–styrenesulfonate (SS) copolymer with ionically bound cationic Brilliant Blue (BB
]. A DMF
solution of the copolymer was used to deposit the ﬁ lm. Solvent was removed from the resulting ﬁ lms in two steps. First, the
plates were placed under a vacuum (at 20°C) for several hours. Then, they were stored in air (also at 20°C) for 7 days. As a
result, the plate surface was covered by (MA)
polymer ﬁ lms that had an absorption maximum at 649 nm in
, if present, would react with BB
The resulting compound BB
practically did not absorb light at 649 nm (the ﬁ lm color faded). This reaction was
reversible (the ﬁ lm returned to the initial color if SO
was removed from the air) [3–5].
Serially manufactured domestic LEDs KIPD 66 (3-mm bulb diameter), AL 307 and KIPD 21 (5-mm bulb diameter),
and KIPD 35 (10-mm bulb diameter) with an emission intensity maximum at 655 nm and nominal input voltage 2 V could
potentially have been used as the radiation source to study the change of light absorption by the polymer ﬁ lms (Table 1).
Bright LEDs (KIPD 21) had the highest light power (up to 3 cd) and lowest emission angle (20°). However, low-cur-
rent LEDs (KIPD 66) required the least energy (nominal DC only 2 mA) .