household, industrial ozonizers and gas analyzers for ozone concentration in water or air.

Maximum permissible values of ozone in the air.

  The olfactory organs sense the presence of ozone in the ambient air at a concentration of 0.01 mg / m3. The MAC level for ozone in the air is as follows:

• Working area - 0.01 mg / m3.
• Average daily concentration in settlements and places where people are 0.03 mg / m3.
• Maximum one-time concentration in settlements and places - 0.16 mg / m3.

The peculiarity of the ozone contained in the air is the low rate of its independent decay. So, for example, at a temperature of 20̊, the half-life is 3 days, and in water, under similar conditions, the indicator decreases to 20 minutes (the time of ozone destruction decreases sharply with increasing temperature). The rapid decomposition of the oxidizer in the latter and its bound state does not require the introduction of permissible ozone values in water, but control over the content is required to ensure complete disinfection.

Determination of ozone concentration parameters
Measurement of ozone concentration in water is carried out by one of the following methods:

• determination of redox potential;

• photometry;

• the use of amperometric sensors;

• titration.

Devices for measuring ozone in air use the following methods during operation:

• the use of substances that chemically interact with ozone or its decomposition products;

• photometry;

• determination of the resistance of a number of metal oxides, etc.

The specific method for measuring the concentration of ozone in water or air is determined by the ease of use, the frequency of taking readings, the financial capabilities of the enterprise and a number of other factors.

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PPM (parts per million) is the fraction of parts per million water molecules, that is, 1 mg / l.

0-50 ppm - ultrapure water (possibly distilled);

50-100 ppm - pure (filtered) water;

100-300 ppm - ordinary (tap) water that has undergone initial purification; 300-600 ppm - hard water;

600-1000 ppm - hard water, unsuitable for drinking;

more than 1000 ppm is a hazardous liquid.