Instrument error and its effect on readings
Infrared pyrometers are used for non-contact determination of the temperature of various surfaces. It can be both thermal devices and freezers. Pyrometers are used by employees of various services when it is necessary to determine the value of the water temperature in the heating system or the degree of surface heating when using built-in heaters.
It is interesting! If the thermometer shows the air temperature in the room, then the pyrometer can determine the temperature indicators of the surface of the walls, floor, ceiling, windows and doors, thereby concluding that it causes heat loss in the house. Although the device is less effective, however, due to its low cost, it is affordable for everyone. With the right and competent approach, it is possible to identify the place of heat leakage in the house, and eliminate it by warming.
One of the main technical parameters of pyrometers is the error value. The cheaper the device, the higher the error. The magnitude of the error is affected, first of all, by the pyrometric sensor, or rather its workmanship. One of the most accurate pyrometers are medical, which are 2-3 times more expensive than conventional ones. The design of medical devices uses high-quality sensors that, with a minimum error, allow you to determine the value of a person's body temperature in a few seconds.
For domestic use, devices with an error of up to 2% are suitable. This is enough to find out the temperature value in pipes, on walls, on the ceiling or floor. The magnitude of the error also depends not only on the quality of the sensor used, but also on the remoteness of the device from the measured surface. The farther the distance to the surface, the greater the error. This property is typical for all types of pyrometers - from the cheapest to the most expensive. The only difference is that expensive models are able to determine the temperature at a distance from the surface up to several meters.
When buying a device, it is also necessary to take into account the limit of temperature measurement limits. If there are no problems with positive values, since on most models the value reaches +300 degrees, then negative parameters sometimes reach -20-50 degrees.
What does the user get from installing a heat meter
The cost of heating increases every year. Some people are trying to solve this problem through a more economical attitude to heat: they put up new windows, insulate their home. Modern double-glazed windows are energy efficient and allow you to save about 30% of heat.
Very often, the owner of the house has to pay a lot of money during the heating season. At the same time, batteries do not always heat the room at the proper level. As a result, a person pays for what he does not receive. In this case, heating meters are a great option to save money. By installing a meter in an apartment, you can save about 40% of the total payment for heating services. The installation of a measuring device pays off within 3 to 6 months of the heating season.
Sometimes poor heating is associated with the negligence of service workers, with the operator's unwillingness to lose money to achieve the required parameters of the coolant. If the apartment has a heating meter, this can be a weighty argument in the event of a lawsuit with utilities.
Go to the State Register of SI
This database of information about approved types of measuring instruments usually has the form of a table, for example, as follows:
| Number in the state register | Name of SI | SI type designation | Period of certificate or serial number | Manufacturer |
| 73016-18 | Gas volume correctors | EK270 | for 3 pcs. with serial number 1116071806, 1116071807, 1116081962 | Elster Gaselectronics LLC, Arzamas |
| 73015-18 | Simulators of vehicle movement parameters | SAPSAN 3M | 30.10.2023 | LLC "OLVIA", St. Petersburg |
| 73014-18 | Measuring amplifiers | QuantumX and SomatXR | 30.10.2023 | Firm «Hottinger Baldwin Messtechnik GmbH», Germany |
Current information of the state register of measuring instruments (state register of measuring instruments) can be found in the section Register of measuring instruments
The state register of measuring instruments is intended for registration and storage of information about measuring instruments of an approved type.
Goals of the State Register of SI:
- registration of approved type measuring instruments and creation of a centralized information register of data on measuring instruments approved for production, release into circulation and use in the Russian Federation
- registration of accredited state centers for testing measuring instruments
- accounting of issued certificates of approval of the type of measuring instruments and certificates of accredited state centers for testing measuring instruments
- accounting for standard test programs for measuring instruments for the purpose of type approval
- organization of information services for interested legal entities and individuals, including national metrological services of countries participating in cooperation on mutual recognition of test results and approval of the type of measuring instruments
The State Register contains the following information about the measuring instrument (columns of the table):
- SI name
- registration number (the last two digits indicate the year of approval of the SI type)
- appointment of SI
- manufacturer country
- manufacturer and his details
- name of the State Testing Center
- certificate validity period
- calibration interval
- verification procedure
MI type approval is carried out on the basis of MI tests, which are carried out by the State Centers for Standardization, Metrology and Testing (CSM).
Maintaining the State Register of Measuring Instruments is entrusted to FSUE VNIIMS.
For information on approved types of measuring instruments approved for use in the Russian Federation (included in the State Register), see our website.
The procedure for maintaining the State Register of Measuring Instruments is specified in the relevant document: Metrology Rules PR 50.2.011-94 "Procedure for Maintaining the State Register of Measuring Instruments"
Link to the relevant section of FSIS "Arshin"
Electromagnetic heating meter
This is an expensive model of thermal devices, and is one of the most accurate devices. The principle of operation of an electromagnetic meter is to pass the coolant through the device, while the electromagnetic field conducts a weak current. This device needs to be maintained, that is, periodically cleaned.
Rice. 4 Electromagnetic heat meters
The electromagnetic device consists of 3 main parts:
- primary converter;
- An electronic unit that can operate both from batteries and from the mains;
- temperature sensors.
In this case, the electromagnetic thermal device can be installed in any position (horizontal, vertical, or at an angle), but this is only in the case when the area where the meter is installed is constantly filled with coolant.
If the diameter of the pipe does not match the diameter of the device flange, then adapters can be used.
General information about metering devices for thermal energy and coolant
Thermal energy and coolant metering devices are called devices that perform one or more of the following functions: measuring, accumulating, storing, displaying information about the amount of thermal energy, mass (volume) of the coolant, temperature, pressure of the coolant and operating time devices.
For metering devices for thermal energy and coolant, a short name is adopted - heat meters.
The heat meter consists of two main functionally independent parts: a heat meter and sensors (flow, temperature and pressure of the coolant) (Figure 1).
Figure 1 - The composition of the heat meter
A heat calculator is a specialized microprocessor device designed to process signals (analog, pulse or digital, depending on the type of sensor used) from sensors, convert them into digital form, calculate the amount of thermal energy in accordance with the accepted algorithm (determined by the heat supply scheme), display and storage (archiving) in the non-volatile memory of the device of heat consumption parameters (Figure 2).
Figure 2 - Functions performed by the heat meter
Flow sensors are the most important element of a heat meter in terms of influencing its technical and consumer characteristics. It is the flow sensor that determines the quality of the heat meter.
As a flow sensor, a functionally completed independent device (flow meter, flow meter-meter or meter) can be used, for which the public name is accepted - a flow converter, or a primary flow converter that can only function in conjunction with a specific type of heat meter.
In the first case, the flow sensor generates a unified output signal (pulse, current), which can be processed by various heat meters, whose inputs are consistent with the output signals of the flow sensor. This configuration of the heat meter to a certain extent ensures the unification of heat metering devices.
The flow transducer consists of a primary and a secondary flow transducer. The secondary flow transducer is an electronic unit that can be structurally combined with the primary flow transducer, or may have a separate version. In some cases, the secondary flow converter is a functional part of the heat meter, and the secondary converter and the heat meter are mounted in the same housing and sometimes on the same board.
There are various ways to measure the flow rate of a heat carrier (heating water), for example: electromagnetic, ultrasonic, vortex, etc. According to the method of measuring the flow implemented in a heat meter, it is customary to briefly call the heat meter electromagnetic, ultrasonic, vortex, etc.
The vast majority of heat meters measure the volumetric flow rate of the coolant and then calculate the mass flow rate based on temperature and density data (temperature is measured, density is calculated).
Usually, pairs of thermal resistances selected according to metrological characteristics are used as temperature sensors in the heat meter, which are connected to the heat meter in a two-, three-, or four-wire circuit. The heat calculator measures the value of the thermal resistance active resistance, compensates for errors introduced by communication lines, and calculates the coolant temperature.
Pressure sensors also have an insignificant effect on the technical and consumer properties of the heat meter, especially since for most practically important applications of the heat meter, the use of a pressure sensor is not necessary. It is obligatory to register the pressure only at sources of thermal energy and at consumers with an open heat consumption system. Typically, pressure sensors have a unified current output of 4..20, 0…20 or 0…5 mA, and the heat meter has an input interfaced with them.
Often, the heat meter does not provide for the possibility of connecting a pressure sensor. If this possibility exists, it should be borne in mind that an additional voltage source may be required to power the pressure sensor if it is not built into the heat meter.
The temperature and pressure of the coolant are the initial parameters for determining the specific enthalpy of the coolant.
Ultrasonic heating meter
This type of meters is most often installed as a common device for apartment buildings.The principle of its operation lies in the ultrasonic signal, thanks to which the device, in fact, takes measurements (using a sensor). This signal is passed through the water. The complete set of this device consists of an emitter and a device that sends a signal. These components are installed one opposite the other.
Rice. 3 Ultrasonic device
An ultrasonic device is best installed in homes with new piping, as it is very sensitive to contamination.
There are such types of ultrasonic heat meters:
Each of these types gives accurate readings only if the water is clean and free of impurities. Any contamination or even air bubbles will affect the readings.
The advantages of this counter include the information content, which is achieved thanks to the liquid crystal display and the fact that when installing this model, the hydraulic pressure does not increase.
But there is also such a minus in the operation of an ultrasonic device: if the power supply is unstable, then it is connected via UPS.
The principle of operation of the counter on the battery
Let us consider in more detail the heating meter how it works, and what factors can affect its functioning.
A heat meter is installed in order to determine the volume of coolant in the radiator, as well as to measure the water temperature level.
If the wiring in the house is horizontal, the unit is mounted on a horizontal pipe. At the same time, one device per apartment is enough. But with vertical pipe routing, a separate meter will have to be installed for each battery.
It should be noted that the heating meter in the apartment is quite accurate. But there are a number of factors that can have a strong influence on the device and cause some error. For instance:
- The circulation of the coolant is disturbed, a low flow rate is observed.
- There is a thermal difference, which is less than +30 degrees.
- The installation of the meter is illiterate. For example, temperature sensors are installed incorrectly.
- The quality of the pipeline, the water is poor. For example, water is too hard and has various impurities like sand, rust.
What are the types of heating meters?
Depending on the installation method, the heating meter can be common and individual. In the case of a common building option, a metering device is purchased one for the entire high-rise building. Despite the fact that the meter is expensive, it will be quite affordable for the owner of each apartment. After all, the total price will be divided among all tenants. Despite the availability of purchasing a heat metering unit, the savings may not be high due to the fact that some apartments may be poorly insulated. As a result, everyone will have to pay.
Therefore, many people prefer to install an individual meter on the heating battery. to pay only for the heat actually received by the apartment. True, such a device is not suitable for every room. For example, installing a meter in an old house with a vertical type of wiring can be quite problematic. After all, the device is installed on the riser. And in such houses there are several of them. Putting a counter on each riser is very expensive. In this case, distributors are used.
Also, all heating meters for an apartment according to the principle of operation can be classified into:
- Ultrasonic. Most often used. They are considered the most accurate, durable and reliable. The error can be caused by particles of debris getting on the signal receiver, the formation of air bubbles.
- Mechanical. Suitable for use in polluted or saline circulating fluids.
- Electromagnetic. Pretty accurate. Differ in stable work.
- Vortex. The principle of operation is that data on the strength of the resulting vortices are compared after the passage of the circulating fluid.
Features of installing a heating meter
It should be noted that self-installation of heating meters in an apartment is unacceptable. This may result in refusal of registration, and the personal account will not be reissued.
It is also important to remember that every four years the unit should be given for inspection
To install the device, you need to carry out a number of actions:
- get permission;
- study the technical conditions;
- create a project, it must be agreed with the heat supply company;
- install the unit.
How much will it cost to install a heating meter?
For those who want to spend money wisely, a heat meter is the best investment option. Of course, the price of the device is considerable. But if you consider that the acquisition pays off quickly enough, then the counter is not so expensive. For a heating meter, the general house price is more affordable than for a unit installed individually for one apartment.
The cost of devices depends on the type and manufacturer. It must be remembered that in addition to buying the device itself, you will have to spend money on its installation. After all, installation should only be carried out by a professional. I must say that the price of heating meters includes, in addition to the equipment itself, some components: shut-off valves, control valve, filter. On average, the cost is from 9000 rubles. If we add to this the cost of installation, the amount can rise to 20,000 rubles.
It is very profitable to buy meters in bulk: at the same time, the price for a heating meter will be slightly lower. This is possible, for example, if other residents plan to install this unit in the entrance for their apartments.
Installing a heating meter
There are special companies that install heat meters, namely:
- They are doing a project;
- Submit documents to the relevant authorities to obtain permission;
- Install the counter and immediately register it;
- Next, test tests must be carried out and the device is put into operation.
If the counter is not registered properly, then its readings are not taken into account. To pay bills, you need to submit indicators, and the receipt comes with the amount at the established rate.
The developed project should include the following points:
- Device (type) model for a specific heating system;
- Necessary calculations for coolant flow rates, as well as calculations of heat load;
- There should be a diagram of the heating system, indicating the place where the meter will be installed;
- The hydraulic resistance of the device must be calculated;
- Calculation of possible heat losses;
- And also be sure to calculate the waste for heat energy.
Vortex heating device
This meter can be installed on pipes, both horizontal and vertical. The principle of operation is to measure the speed and number of vortices. That is, it is an obstacle in the way of the water flow, the water goes around the obstacle and as a result, vortices are created. It is not sensitive to the manifestation of various blockages, such as rust, scale, etc. This counter can give incorrect readings only if there is air in the system.
Complete set of the vortex heating device:
- Counting mechanism;
- Frame;
- Plates;
- Heat fairing;
- Filter.
Rice. 5 Vortex device
The vortex counter is installed horizontally between two pipes.
Purpose and classification of thermal control devices
In any technological installation, including a boiler, there are quantities that characterize the quality or productivity of the process, the so-called process parameters.
In a boiler plant, the main parameters are temperature, pressure, water level (for a steam boiler), fuel and coolant consumption.
Monitoring of the operating parameters of the boiler plant is carried out using automatic instrumentation.
Automatic measuring devices allow you to conduct the technological process rationally, observing the most economically advantageous mode. In addition, control and measuring devices make it possible to protect the boiler plant from deviations from the normal technological process that are dangerous for it.
Automatic measurement of technological parameters allows for fast and accurate readings and facilitates the work of maintenance personnel.
Depending on the type of measured parameter, thermal control instruments are divided into thermometers, pressure gauges, vacuum gauges, flow meters, gas analyzers.
The measurement consists in comparing the current technological parameter with the standard of this parameter. However, it is not the parameter itself that is compared, but some intermediate value into which the value of the measured parameter is converted. This value can be mechanical (eg displacement), hydraulic (eg pressure), electrical (eg voltage).
Measurements can be made by contact or non-contact method. The sensitive element of the device in the contact method directly comes into contact with the controlled medium, and in the non-contact method it does not come into contact.
Measurements are carried out by two methods: direct and indirect (indirect) measurement.
Direct measurement method lies in the fact that the measured parameter, converted into a certain value, has an effect on the reproducing device according to the scheme of Fig. 10.1.
Reproducing-
Rice. 10.1. Direct measurement scheme
In this case, the perceiving element reacts to the value of the parameter. The impulse (signal) from it is amplified and transmitted to the reproducing device.
The amplifier may be absent if the impulse from the receiving device is sufficient to operate the playback device.
In the direct measurement method, energy is transferred through the measurement circuit. Therefore, the readings of the measuring device will depend on the environmental conditions. So, for example, the temperature will affect the electrical resistance of the connecting wires and, consequently, the operation of the device.
Indirect measurement method consists in the fact that the output value of the perceiving element is compared with a known value of the same nature, and already by this value (after amplification, if necessary), the value of the measured parameter is reflected by the reproducing device, as shown in Fig. 10.2.
reproducing
Rice. 10.2. Scheme of indirect measurement
The indirect method is more complicated, but has the advantage that no current flows through the measuring device and through the wires to it at the time of measurement, which ensures high measurement accuracy.
The instrument can display the current value of the parameter, register it, or perform the necessary actions with the received data, for example, integrate (summarize) the flow readings.
Signaling elements can be attached to control and measuring devices, then these devices will also be signaling.
Automatic control and measuring devices can be of local or remote action.
In local instruments, the measuring device with the indicating device is combined in one housing with the receiving element or is connected to it by a short communication line in the form of a tube, capillary, wire, etc.
Remote action devices have a special device for transmitting readings to one or more so-called secondary devices (indicating, self-recording) installed at a more or less significant (up to hundreds of meters) distance from the place where the parameter is measured. The use of remote action devices allows you to focus the readings on the central panels, which greatly facilitates the monitoring of the boiler plant.
Scope of application
Laser thermometers for measuring the surface temperature of objects under study are widely used. Today they are indispensable in industry, construction, various scientific research. They are used in almost every branch of modern production. Laser pyrometer is required:
- in metallurgy, steel industry, where contact with the melt is impossible;
- in the food industry, everyday life (for example, to measure the temperature of hot dishes, body or dishes);
- in work on the repair of gas and oil pipelines;
- in electric and thermal power engineering, military and civil engineering;
- for checking electrical equipment (for example, split systems);
- when examining the internal combustion engine, bearing elements that make up the computer.
In addition, laser non-contact temperature meters are indispensable when inspecting infrastructure facilities, as well as refrigeration equipment. They buy measuring equipment based on predetermined tasks. They are equipped with security and fire brigades, they are needed to assess the temperature conditions during the storage of medicines and food products.
Types of thermal heating devices
The main types of heat meters include:
- Tachometric or mechanical;
- Ultrasonic;
- Electromagnetic;
- Vortex.
And there is also a classification by scope. For example, industrial or individual.
An industrial heat meter for heating is a common house (in apartment buildings) device, it is also installed at production facilities. This unit has a large diameter from 2.5 cm to 30 cm. The range of coolant quantity is from 0.6 to 2.5 m3 per hour.
An individual heating device is the unit that is installed inside the apartment. It differs in that its channels have a small diameter, namely no more than 2 cm. And also the range of the amount of coolant becomes from 0.6 to 2.5 m3 per hour. This meter is equipped with 2 devices, namely, a heat meter and a meter for hot water.
Table of contents
ACCOUNTING
AND CONSUMPTION REGULATION
ENERGY RESOURCES 3
7.1
Electrical energy metering systems 3
7.2
Regulation and accounting of thermal energy,
types of appliances used in the Republic
Belarus 7
7.3
Basic Instrumentation Measures
accounting for the use of fuel and energy resources 10
7.4
Accounting for the consumption of cold and hot water 12
7.5
Gas metering 14
BASICS
ENERGY MANAGEMENT AND AUDIT 18
8.1
Essence, goals, objectives and organization
energy management and
energy audit at the enterprise 18
8.2
The procedure for conducting an energy
audit at the enterprise 21
8.3
Energy balance 24
HOUSEHOLD
ENERGY SAVING 27
9.1
Energy saving in building lighting 27
9.2
Electrical appliances and their efficiency
use 29
9.3
Improving the efficiency of systems
heating. Autonomous power plants 31
9.4
Air heating systems 34
ENERGY SAVING
IN INDUSTRIAL AND PUBLIC BUILDINGS
AND FACILITIES 37
10.1
Heat losses in buildings and structures 37
10.2
Thermal insulation of buildings and structures 39
10.3
Energy certification of buildings,
monitoring of built-up areas and
expertise of thermal protection projects 41
10.4
Insulating characteristics of glazing.
Double-glazed windows 43
ENERGY SAVING
AND ECOLOGY 47
11.1
Environmental problems of energy 47
11.2
Greenhouse effect 49
PRIORITY
DIRECTIONS OF ENERGY SAVING POLICY
IN THE MAIN SECTORS OF THE COUNTRY'S ECONOMY 56
12.1
Development of fuel and energy industries
complex 56
12.2
Energy saving measures in
main sectors of the economy 57
12.2.1
Industry 57
12.2.2
Agriculture 58
12.2.3
Construction complex 59
12.2.4
Chemical and petrochemical industry 61
12.2.5
Energy 61
12.2.6
Housing and communal services 63
LIST
USED AND RECOMMENDED
LITERATURE 66
LECTURE 7 ( 2 hours)
