Water and heat meters
Supply. General Specifications "approved in 2000, but the requirements for testing are not met. In particular, the instruments do not pass the EMC test. None of the test centers conducts tests prescribed by GOST for the purpose of checking the security against unauthorized access to the memory of devices. To prove later that the consumer deliberately distorts the readings of the instruments is very difficult.
There are many opportunities for fraud. This is due to the fact that the heat meter is rather complicated in terms of the device, the algorithms of operation, installation, and operation.
There are a number of ways to correct the readings of the instruments. The simplest method is sometimes used by the owners of household plots to reduce the cost of water spent for irrigation. The consumer buys the cheapest and unreliable (according to neighbors and friends) water meter, agrees its application with the supplier of water. In accordance with domestic standards, the minimum flow rate, fixed by the water meter, is 30 l / h. Consequently, the tap is opened in such a way that the flow rate is less than 30 l / h. At the same time, the meter does not record the water analysis at all, ie, by installing the device, the consumer is able to legally not pay for water: at a flow rate of, for example, 20 liters per hour, 480 liters of clean drinking water are absolutely free!
In urban apartments tenants practice a slightly more complicated way. When installing the meter, it is necessary to install a strainer with a stopper that is not sealed, as the cleaning of the filter is periodically required. The consumer screws a flexible hose (piping) into the place of the removed drain nut of the filter and receives water bypassing the counter. In the event that the Vodokanal inspector comes to check the meter (which is very rare), it is enough to unscrew the hose nut and put a regular stopper - this requires several minutes.
For the same design of the water accounting unit, there is a simpler method: a thin wire is attached to the glass of the mesh filter and passed through the pipe along the water. The wire brakes the rotation of the turbine of the meter, and the readings are significantly underestimated.
Most of the currently used water meters are so-called "dry winds". They consist of two parts: a turbine rotating in water, and a counting mechanism separated from the turbine by a sealed partition. One or more small magnets are attached to the turbine. Water rotates the impeller, under the influence of the rotation of the magnets behind the sealed partition, a metal ring rotates, the rotation of the ring is transferred to the counting mechanism. The essence of the next method of underestimating the readings is the braking of the impeller by installing external magnets, the position of which is determined experimentally.
The considered ways of correction of indications of water meters force us to treat the positive conclusions of various organizations about the results of their implementation in a different way. It is clear that if you install residential water meters in a residential quarter, then the amount of their readings (for example, per month) will be less than the calculated value determined by the relevant standards. This is not questioned. However, in none of the reports or in one of the numerous articles did the authors mention that somewhere after the installation of residential water meters, the total water consumption of the city, district, and township decreased. In practice, simultaneously with the introduction of water meters, an imbalance between the results of the recording of output and consumption is growing, and the manipulations with the instruments discussed above are forcibly written off for losses in distribution networks.
More varied ways to adjust the readings of heat meters. The heat meter consists of three main units: a flowmeter, thermal converters, a heat calculator, and corrections can be made by manipulating any of the blocks.
The tachometric flowmeters of heat meters have the same adjustment options as those mentioned above for water meters.
Electromagnetic flowmeter structurally consists of two magnetic coils installed under and above the tube, two measuring electrodes located horizontally. The coil is supplied with an alternating voltage of known frequency and shape. A signal proportional to the flow rate of the liquid is removed from the electrodes. To correct the readings of the device outside the flow sensor, additional magnetic coils are installed, the voltage of which is supplied in antiphase to the voltage of the coils of the device. Thus, the useful signal is suppressed and the reading is underestimated. Fortunately, this method has not yet received wide circulation, since it requires a certain qualification of the performer.
The vortex flowmeter constructively consists of a triangular prism vertically mounted in the tube, a measuring electrode inserted into the pipe further downstream of the liquid, and a permanent magnet mounted outside the pipe. Manipulations are reduced to distortion of the magnetic field of the permanent magnet of the flowmeter. To do this, use a set of permanent magnets.
Their location is chosen empirically. In this way, it is possible to significantly raise the lower limit of the measuring range of the instrument. Another way of lowering the readings of the vortex flowmeters is to swirl and curl the flow of water, for example, by displacing the gasket between the instrument flanges and the pipeline when mounting.
An uncomplicated but effective way of underestimating the heat meter reading is related to the operation of thermal converters. They are installed in the supply and return pipelines and are connected by communication lines to the heat calculator. By connecting a resistor with variable resistance parallel to the thermocouple mounted on the supply line, it is possible to lower the temperature of the water supplied from the heating system. And the size of the required "economy" is regulated by the selection of the resistance of the resistor.
The way of winding the water meter with a vacuum cleaner:
When installing the meter, usually before it is installed a strainer with a stopper, which is not sealed. From time to time it has to be cleaned. By this time it is convenient to time the "winding" of the counter. The idea is simple - to pass through the counter a stream of something (preferably free) in the opposite direction. We use air for this.
So, close the valve before the filter and remove the plug from the filter.
We take a vacuum cleaner, insert its hose into the outlet (if the design of the vacuum cleaner allows it) and "blow" it, for example, into the window (to remove dust).
We open the tap on the mixer and connect the hose from the vacuum cleaner to it. The connection point can be sealed, for example, by winding a rag onto the spout of the mixer or by clamping the junction with your hand. Some of the air will have to be released anyway, so as not to burn the vacuum cleaner. Turn on the vacuum cleaner and turn the meter back. Speed is regulated by releasing a portion of the air at the point where the vacuum cleaner hose is connected to the tap. This must be done necessarily, otherwise the vacuum cleaner can burn out from the lack of air to cool the engine. On domestic cranes may not work, because they have a gasket attached to the rod freely and can act as a check valve.
This method is applicable if the vacuum cleaner is an old type. New can only "suck." In this case, connect it to the filter instead of the plug. It is necessary only to watch, not to "pump" the water left in the pipes. Otherwise, the vacuum cleaner will fail. To avoid this, a separation vessel can be used. To do this, take the jar, close it with a plastic lid, make two holes in the lid. One must fit the hose from the vacuum cleaner tightly (shallow), the other is also tight the hose that goes to the filter (this hose is inserted almost to the bottom of the jar). Now the water, accidentally left in the pipe, will be collected in a jar, and clean air will go into the vacuum cleaner. (Anna 03.01.05)
Method of stopping the water meter with a magnet:
The use of a magnet to stop the water meter SGV-15. Two magnets from the speakers are glued to the plate with an opening with which the entire device is worn on the meter body. It is tested that the magnets used in the hard disks of the company are stronger and installed simply on the stack opposite the axis (simply attached) in general stop the meter.