A thermostat is a device that allows you to maintain a constant temperature in an enclosed space. It is used in bacteriological and virological laboratories for cultivating microorganisms at a certain temperature, as well as in clinical laboratories for carrying out various chemical analyzes.
Thermostats are water and air. Both types of thermostats are a metal cabinet with double walls (Fig. 1), between which there is a coolant (air or water). The preservation of heat is provided by a gasket made of insulating material (asbestos, fiber, cork, felt, etc.). Thermostats have an electric heater. In water thermostats, it is separated from the water by a metal casing. A necessary element of any thermostat is a thermostat (contact thermometer), through which the heater is automatically turned on and off and thus maintains a constant temperature in the thermostat.
The deviation from the set temperature in the range of 28–39 ° is ± 0.6 °. If a more stable temperature is needed, use an ultra-thermostat (Fig. 2).
An ultra-thermostat is a metal tank with a lid on which a heater is mounted, contact and control thermometers, openings with connections for water inlet and outlet, a hatch for introducing test samples, and an electric motor with a stirrer. The temperature stability is achieved by vigorous mixing of water (coolant) with the help of an electric motor and automatic regulation with the help of a contact thermometer.
Fig. 1. Dry-air thermostat Ts-450: on the left - general view; on the right is a diagram. 1 - contact thermometer; 2 - housing; 3 - removable shelf; 4 - working chamber; 5 - middle camera; in - the electric heater; 7 - heat-insulating material: 8 - stand; 9 - grounding; 10 - adjustment toggle: 11 - power cord; 12 - panel; 13 - outer door; 14 - outer door handle; 15 - inner door; 16 - constipation of the inner door; 17 - casing: 18 - control thermometer.
Fig. 2. Ultra-thermostat TS-15 M: 1 - contact thermometer; 2 - control thermometer; 3 - hatch with a lid of rings for the studied samples; 4, 5, 8 and 9 - pipes for water inlet and outlet; 6 - flexible coupling; 7 - bracket; 10 - electric motor.