SU98837A1 - Ionization gas analyzer - Google Patents

Description

The known ionization gas analyzers, consisting of a radioactive ion generator and an ionization chamber through which the test gas is sucked, are based on measuring the change in ion mobility caused by the presence of an impurity in the gas. The disadvantage of these gas analyzers is the formation of ions of both signs inside the chamber volume and the measurement of the total effect created by them. Since the mobility of positive ions is less dependent on impurities than negative ions, at low percentages of 1x the impurities of gases, vapors and fumes to the test air or gas, the sensitivity of such gas analyzers is relatively low.

In order to increase the sensitivity of this type of ionization gas analyzers, it is proposed to perform a gas analyzer so that only negative ions get into the ionization chamber, whose mobility is more dependent on impurities than 1O. This is achieved by positioning the generator's radiating negative electrode from the receiving positive electrode, mounted on the inner wall of the ionization chamber, at a distance slightly greater than the mean free path of the alpha particles in the air. To eliminate the influence of external factors (temperature, pressure, gas flow rate, constant impurities to gas) it is proposed to introduce two analyzers into the gas flow in series or in parallel, the generators of which create: one negative and one positive in the corresponding ionization chambers, included on the bridge circuit.

FIG. 1 and 2 schematically show a single ionization gas analyzer and, accordingly, a differential type gas analyzer.

As can be seen from the FNG. 1, proposed: ha: {oana.hzizator consists of a radioactive generator |) and 1, nopiz. tsopnoy camera 2 (flat, pilin № 98837-2 -

spherical or other shape), an amplifying circuit 3, an electrical measuring device 4 and an air-cushioned pump (not shown in the drawing). The generator i of the uminolar (negative) ions has an emitting electrode 5, covered with radioactive layer 6, emitting alpha or soft beta rays. At a distance slightly longer than the mean free path of alpha particles in air at normal pressure, a receiving electrode 7 is installed on the inner wall of the copy chamber 2.

E. hectrodes 5 and 7 elect)) are ically isolated from each other and between the names of the applied DC voltage with polarity shown in the drawing. Alpha rays create ions of both signs and there are those and other ions on the length of the sample of alpha particles, but with the plus sign and the receiving electrode 7 in the region adjacent to the symbol, i.e., only negative ions in the ionized opioid chamber. If the speed of the i-ioriOB in the par 11) field of the electri- cal field is less than the velocity of the gas flow, then the overwhelming part of the negative ions does not reach lek-type 7 and is entrained by the gas flow. Selecting a certain cciornoujeiiiic between the velocity of the field and the velocity of the gas flow, we can) | ()) K) the beam in the gas flow is pure uni-gy; I believe in the design.

ii; i gas flow in an iopization chamber 2 installed on the street; -; a) more powerful (measuring) electrodes 8. Applying to these,. By electroplating the corresponding potential difference of a continuous or non-intermittent current, it is possible to ensure that, in the absence of any impurity, all) ion: j -nni are captured. With palichpm: impurities, the mobility of otpiaiac / rijinjix of priests becomes:: 5O many times more shortly, and with the same values and xn (: n And the gas current of the negative 1e ions is carried away by the gas flow.) in the absence of impurities in the measuring electrode electrodes, a current flows, which creates a voltage drop across the conjugate 9, which is amplified by the electronic CxeMoti 3 and is indicated by an electrical measuring device 4. As soon as the current flowing through the resistance 9 decreases, and some coppeptration becomes equally m zero. Electric-scale device 4 can be a graduated in parts per weight percentage or content of impurity is in the air or other gases. If necessary, the anode circuit of the amplifier may be included relay which nr achieving onredelennoy impurity concentration gives a light or sound signal.

FIG. 2 schematically shows a differential ionization gas analyzer that allows to exclude the influence of external (() actors (temperature, pressure, gas flow rate, constant impurities to gas) on the electric meter reading device.

The gas analyzer has two analyzers connected in parallel (possible successively) into the gas flow. The generators li and b of these analyzers create one (li) -positive and another (b) negative signals in the corresponding ionization chambers 2i and 22. The collecting (measuring) electrodes 8i and 82 of these chambers, together with the resistances 9i and 92, form a bridge, diagonal through which the electrical measuring circuit is switched on through the electronic amplifying circuit 4. In the absence of the mixture in the analyzed gas, the mobility of the positive and drift ions is almost odipack, the bridge is in equilibrium and the electrical meter shows zero. In the presence of impurities, the mobility of negative ions decreases, while the α-mobility of positive ions remains almost unchanged. This entails the imbalance of the bridge and the deviation of the electrical measuring device, a normal concentration of impurities. Since the dependences of the mobility of positive and negative ions

Because temperature and pressure are the same, then with a differential-type gas analyzer, errors due to these factors, as well as a change in the flow rate, are automatically excluded. Also excluded is the error caused by the water vapor, carbon dioxide and other gases that are constantly present in the air, since the changes in mobility caused by them are the same for the ions of both signs.

Present Invention

Claims (2)

1. The ionization gas analyzer, consisting of a radioactive ion generator and ionization chamber, through which the apicalized gas is sucked, characterized in that, in order to increase the sensitivity of the gas analyzer, the radiating negative electrode of the generator is located from the receiving positive electrode mounted on the inside wall of the ionization chamber at a distance somewhat longer than the free path of alpha particles in the air, so that in the region adjacent to the receiving electrode, i.e., in the ionization the chamber reached only negative ions, whose mobility is more dependent on impurities than positive ions. 2. The ionization gas analyzer according to claim 1, characterized in that, in order to eliminate the influence of external factors (temperature, pressure, gas flow rate, constant impurities to gas), it consists of two analyzers introduced into the gas flow in series or parallel, the generators of which create: one-negative and another-positive ions in the corresponding ionization chambers, connected by a bridge circuit. Analyzing Kbiu gas To pump FIG. one // pump