SU541113A1 - Method for checking optical absorption gas analyzer - Google Patents

Description

The invention relates to the field of industrial optical absorption (e.g., infrared) determination of radiation absorbing gases and can be used to test optical absorption analyzers of general industrial value. There is a known method for checking absorption gas analyzers using test gas mixtures. A disadvantage of the known method is that the error in checking the middle of the measurement range is unacceptably high. The closest technical solution is a method for checking an optical absorption analysis by successively passing gas mixtures with a determined component Ci and Ca through the gas analyzer system and determining the maximum difference between the indicators on the scale of the meter and the corresponding concentration values. However, this method also gives an unacceptably high error when checking the middle of the measurement range of the gas analyzer. The purpose of the invention is to reduce the measurement error of the gas analyzer. The goal is achieved by filling the p vessels with a mixture with a concentration of Cb (mn) of vessels - a mixture with a concentration of Ca, simultaneously pushing the contents of all t of vessels into the gas system, and the actual set value of the concentration is found by the formula / - i; -f Cy-ttg where | l is the ratio of the volume of p vessels to the volume of (m p) vessels, then the value of the output signal is measured with various combinations of p vessels from t, these values are added and the resulting amount is divided by the total number of different combinations from t of vessels according to n, equal to: t (t - 1) .., (t - n + 1) t - 1-2.3 ... P Consider as an example a test of a gas analyzer with a measurement range from 0 to 100% carbon monoxide . The lower limit of measurement of such a gas analyzer is checked with nitrogen, and the upper limit of measurement is checked with carbon monoxide. If these gases are cleaned by a known method, then the error in checking the limits of measurements will not exceed the error in preparing the concentration of carbon monoxide, i.e., 0.1% relative to the upper limit.

The proposed method has a negligibly small error in obtaining a given value of intermediate concentrations.

Let us consider as an example the self-elimination (autocorrection) of the influence of the nonidentity of the vessels used. Let, for example, use three vessels (), the first and second of which have volumes V, and the third - (F + AF).

Fill the first vessel with nitrogen and the other two with carbon monoxide. Then push these components gradually and simultaneously into the gas system of the gas analyzer. If the total volume of the mixture obtained is significantly larger (for example, by the order) of the gas analyzer gas system, then skipping the mixed components at a low speed (it can be selected experimentally) after some time we will receive in the working chamber an almost steady-state concentration value (and steady-state value of the output signal) equal to

CiV -fCa

2V + AV

with

, +. 1

one

2K + DK2V + & .V

If nitrogen is taken to the second vessel and carbon monoxide to the other two, and then these gases are forced out into the gas analyzer gas system, then the established concentration value is equal to:

10096

V

+ 1

2V + AV

And, finally, if the nitrogen is a vessel, and carbon monoxide, then these gases should be transferred at the end of the process to the following values:

C, (V + DY,

+ Sz

27

 - V + AK

1 2V

It1K, as a result of the described | Above mixing, three steady-state values of concentration (C, C) were obtained. Each of them is obtained with a certain combination of vessels (the number of various combinations of three vessels is equal. Each of the obtained

concentration values are dependent on remote control. However, the mean value does not depend on AV. Average value is

7 C + C + 2-10096.

Sz3

Each time the concentration is determined (C, C and C), the output signal is measured. Each of the obtained signal values depends on AV. However, it can be shown that the average of these values does not depend on AF (as well as the average concentration). The above case of using three

15 vessels. However, the obtained conclusion (independence of the mean value from the degree of vessel identity) is also valid for other values of m. In addition, the effect of unequal sorption and desorption of gas by the inner walls of the vessels is also eliminated.

Claims (1)

Invention Formula The method of testing an optical absorption gas analyzer for chunks of sequential passage through the gas system of a gas analyzer of control gas mixtures with concentrations of a detectable component equal to Ci and C2, and determining the maximum value of the difference between the readings on the scale of the meter and the corresponding concentration values, characterized in that the purpose of reducing the verification error, fill the n vessels 5 mixture with the concentration of Cb (mn) of vessels with a mixture of concentration of Ca, simultaneously push the contents of all tons of vessels into the gas system, and the actual steady-state value of concentration is found Formula f Cta + Sa  -one (A-b 1 where (L is the ratio of the volume p of the vessels to the volume (mn) of the vessels, then the value output signal with various combinations n vessels of t, add these values and the resulting amount is divided by the total number various combinations of tons of vessels according to claim equal to  - ni (m- 1) ... (t - / g + 1) 1-2-3 ... "