The film tells about the structure and operating principle of temperature measuring devices and is intended as a teaching aid for students of vocational schools.
Meteorological station.
Winter.
A station worker takes readings from instruments.
Open-hearth shop.
The concept of temperature.
Measuring temperature in a laboratory.
The unit of temperature measurement in Celsius.
The thermodynamic scale of temperature measurements, expressed in Kelvin.
The reference point temperature of this scale is defined as 273.15 K. A red-hot metal ingot moves along a conveyor.
Examples of expansion thermometers.
Household thermometer.
Thermometers with an external scale, with an embedded scale, and rod thermometers.
When heated, the liquid expands and rises along the capillary.
The measured temperature is counted from the scale.
Examples of technical thermometers.
Technical mercury thermometers that measure temperatures from minus 30 to 500 degrees Celsius.
Since the boiling point of mercury at normal pressure is 358 degrees Celsius, the capillary is filled with an inert gas under pressure to increase the boiling point of mercury.
Mercury electric contact thermometer.
This thermometer is used to signal an increase or decrease in temperature, as well as to turn on automatic control systems.
In terms of design, they are similar to technical thermometers, but have metal contacts.
One of the contacts is soldered at the bottom of the capillary, and the other moves along the capillary when a certain temperature needs to be set.
A cartoon explaining the operation of such a thermometer.
Low temperatures are measured by thermometers filled not with mercury, since it freezes at a temperature of minus 39 degrees, but with ethyl alcohol, toluene (minus 100 degrees Celsius), pentane (minus 190 degrees Celsius).
Bimetallic thermometer.
It uses a bimetallic plate.
A cartoon explaining the operation of such a thermometer.
Bimetallic thermometers with a plate element are used in industry.
A thermometer with an element in the form of a bimetallic spiral is used to measure the ambient air temperature.
Manometric thermometer.
The device of such a thermometer.
A cartoon explaining the device and operation of a manometric thermometer.
Manometric thermometers are either indicating or recording, with a recording device and a moving chart paper disk.
Examples of the use of manometric devices in industry.
A cartoon explaining the operation of recording manometric thermometers.
Thermometer, International Practical Temperature Scale, Thermodynamic scale
A thermoelectric pyrometer is demonstrated.
Such measuring devices measure temperature in industry.
A cartoon explaining the operation of a thermoelectric pyrometer.
Platinum-rhodium-platinum thermocouple.
Chromel-alumel, chromium-capel and other thermocouples.
Standard platinum-rhodium-platinum thermocouples are used to calibrate working thermocouples.
Verification of a thermocouple in laboratory conditions.
Secondary devices measuring the electromotive force of a thermocouple are millivoltmeters and electronic potentiometers.
The scale of the devices is graduated in degrees Celsius.
In addition to thermoelectric immersion thermometers, there are surface thermocouples.
An employee measures the temperature of the working surface of the unit by applying the junction of the thermocouple to the measured area.
A secondary device showing the value of the measured temperature is a portable millivoltmeter.
Scale of the device.
A cartoon explaining the structure of such a secondary device.
Millivoltmeters are divided into indicating and regulating.
A more accurate method for measuring the electromotive force of a thermocouple is the compensation method.
A cartoon explaining the compensation method.
The potentiometer, the main part of the thermocouple, has become electronic, automatic and has become widespread in industry.
Potentiometers are point and multipoint and cover a general temperature range from minus 50 to 1800 degrees Celsius.
Potentiometers with an accuracy class of at least 0.05 are used to check millivoltmeters and electronic potentiometers.
Examples of electrical resistance thermometers.
Such thermometers are used when high measurement accuracy is required.
The operating principle of such thermometers is based on the property of metal conductors to change their electrical resistance with a change in temperature.
The material for the sensitive element can be copper or platinum.
A cartoon explaining the design and operation of electrical resistance thermometers.
Thermoelectric pyrometer, Electrical resistance thermometer
Secondary devices for measuring temperatures with resistance thermometers are devices of magnetoelectric systems of various designs called logometers.
Cartoon explaining the operation of the logometer measuring system.
In addition to logometers, common devices for measuring temperature are electronic balanced bridges.
The operation of such devices is based on the principle of changing the resistance of a balanced bridge.
Cartoon explaining the operation of a bridge circuit.
Thermometer scale.
Electronic bridges are divided into indicating and self-recording, and by the number of measurement and recording points into single-point and multi-point.
By the shape of the diagram on which the recording is made, electronic bridges are divided into devices with a strip or disk diagram.
A steelmaker uses a radiation pyrometer to measure the melting temperature from a long distance.
Radiation pyrometers do not require contact with the measured environment.
Cartoon explaining the operating principle of the pyrometer and its design.
A millivoltmeter with a scale in degrees is used as a indicating element.
Loading scrap metal into a furnace.
Radiation pyrometer.
Such a pyrometer is used as a stationary device for long-term continuous measurement, recording and regulation of temperature.
They are based on measuring the total energy of radiation of a heated body.
Cartoon explaining the operation of a radiation pyrometer.
Rolling mill.
Photoelectric pyrometer.
This device is capable of measuring, recording and regulating the temperature of moving heated bodies.
They are used stationary for long-term and continuous monitoring of temperature in a specified location.
Metallurgical production.
Steel casting, rolling ingots into blanks.
Alternating frames with various temperature measuring devices.
Resistance thermometer, Logometers, Balanced bridges, Pyrometer