The principle of operation of electronic scales

Nowadays, electronic devices are replacing mechanical in almost all areas of activity. Electronics are more convenient, more practical, more elegant, although they are inferior in terms of price acceptability and reliability. But for scales this statement is not quite applicable. Scales - a device, without which it is difficult to do both at home and in industry, by analogy with other devices, they can also be mechanical and electronic. The principle of operation of the former is quite simple and transparent, with regards to the latter - many questions and ambiguities. Let us try to understand how floor electronic scales work and what is the order of actions if they suddenly fail.

Design

Electronic scales include:

• load cell;
• display;
• circuit board with microcircuit.

Display intended to display weightThere are also models with the ability to record indicators of different time periods for later comparison. And in the most modern and expensive models, a lot of sensors are built in, allowing to determine the internal structure of the body according to the percentage of fat, muscles and bones.

Body material

Most often the case is made plastic or glass. Glass devices are certainly safer and more attractive outside, however, care for them should be very careful. It is enough to drop a cup on them, and the devices will fail forever. At observance of all rules on operation, products from glass will serve you for many years. There are also scales made of wood, they are very pleasant for tactile sensations, but not everyone can afford the price of such a device. The same can be said about the "stone" products, heavy and extremely expensive, albeit spectacular in appearance.

Internal organization

The principle of operation of electronic scales is completely different from the basics of the functioning of mechanical copies. Under each leg there are frames that react to any changes. It's easier to say when a person gets up on the device,these frames are deformed in a special way and give the result. Moreover, they are deformed in such a way that it is impossible to mark these changes with an eye or even with a level.

Microscopic plate - strain gauge, less than 2 cm wide is the main sensor unit of the floor and any other electronic device.

This plate is attached to the frame with glue or compound. Three wires emanate from it, providing resistance. When placing something on the device, the frames in the corners, bend and distribute the excess weight among themselves. Through the summation of the data of each instrument and the total value is calculated.

The bridge itself is a quad, on each side of which a resistor is attached. In this case, power passes through one diagonal, and readings are transmitted through the other. Electricity is moving along the wires. Scales arranged in such a way provide maximum protection of sensors, which can be damaged only through serious mechanical impact.

What to do if the scale is out of order

The main problem of electronic device failure is related with strain gauge malfunction. If the maximum weight is exceeded, the structural elements, namely the frame, simply bend. To restore performance, simply straighten them.

If outside it is impossible to install the device, it will be necessary to arrange a test with a tester.

To do this, each sensor must be disconnected from the board, and then measure the resistance of all three wires. If in some angle the resistance is different from the norm, then the cause of the fault is found. After that, disconnect the plate secured with glue. We do this very carefully, because any mechanical damage will negate all efforts, and causes a complete breakdown of the node.

Inside we see a copper plate with three wires. It so happens that one wire came off. In this case, the restoration of the mount and return the performance of the entire unit. And it happens that the sensor just died. Then you need to purchase a new one. As a rule, this is not a problem - there are a huge number of various strain gauge models applicable to any type of scale on the market. The only nuance that may arise later is the need do calibration. If you do not pick up and adjust the sensor according to the required parameters, the device will not work.

Calibration

The load cell is unique in its structure, and even if we compare the products of the same batch and the same manufacturer, you can see the differences, the connections of the bridges will still have some kind of error. With calibration, this error is eliminated.

Given the fact that the total weight is calculated by summing up the readings, you can quite exclude from the process one sensorif it is faulty. This is done either by releasing it from the load, or by simulating the desired values ​​using simple resistors. The first option is suitable for cases when the sensor is incorrectly measured or incorrectly calibrated. The second involves the disconnection of a faulty node, after which its measurement will be perceived by the device as a zero value.

Virtually anyone can repair electronic scales because their device is nothing more than a set of resistors and a board.

Models

There are various models of electronic measuring instruments on the market. Highlight the most popular:

1. Medisana 40419 TargetScale. Multifunctional scales worth about 15,000 rubles.It is possible to synchronize them with any gadget that allows you to view the readings in front of you, and not under your feet. Allow you to display graphs by weight, body fat, blood pressure, body temperature, sugar level. Very interesting modern design and at the same time it has a simple and convenient control.
   
2. Tefal PP 1110. The inexpensive scales which platform is made of glass. Maximum weight - 160 kg, measurement accuracy within 100 grams, automatic on and off function. They do not impose requirements for flooring - they work on carpets, tile and linoleum. A simple model for which the functionality described in the first model is not available, however, the price is absolutely affordable.
   

3. SUPRA Bss-6200 GN. A budget device that allows you to calculate body mass index, fat content and muscle.
   

4. Beurer Bf-100. The most accurate copy, has 8 electrodes, which transmit information to a computer that can memorize data for several users.
   

Electronic scales - the necessary device for regular use. They allow you to control body weight, fat and muscle composition, and if we talk about luxury-class models, then other important vital signs.By purchasing a quality item, you can save on acquiring other devices and guarantee the accuracy of the measurements obtained. And having studied the characteristics of electronic scales and the principle of their work, you can in a short time eliminate any problems that have arisen in their system.