Electrical measurements have a high degree of accuracy, reliability, simplicity and cheapness.Therefore, electrical appliances have been widely used in the measurement and non-electrical quantities.
in the electrical system that measures the value of non-electric, includes the main components, such as: the sensor (converter), intermediate devices, and indicator.
electrical measurements of non-electrical quantities - is essentially a conversion of the sensor non-electrical quantities, say, changes in the level of liquid, speed, temperature, and so on. N., In a change of electrical quantities: resistance, voltage or current, as measured by the indicator, which is a simple The electricdevice.
instruments used for electric measurements are divided into two categories:
- analog ("tseshki") - they are the result of the measurement on the scale of the device indicated by the arrow;
- digital - they analog-digital converter converts the input signal into a digital value and outputs it to the LCD panel.
Today, digital devices have replaced analog, we can say, completely, because, first of all:
- they are easy to use (as opposed to analog (arrow), they have no concepts such as measuring range, or the graduated scale of the device inwhich is necessary to understand);
- they are much more accurate analog.
It should be noted, and the advantage of such devices: electrical measurement can test non-electrical quantities, even in hard to reach places or at a considerable distance.
consider two specific examples of how to carry out electrical measurements using devices that measure non-electrical quantities.
wood moisture meter
As wood - hygroscopic material, that a change in the parameters of the medium, changes its moisture content - one of the properties of wood that are so important when it is used in the finished product.Therefore, the wood is dried to a uniform state with a view to future operating conditions.
One method of measuring the moisture content is to use elektrovlagomerov.The principle of operation consists in measuring the moisture moisture, based on - the electrical properties.With the device it is possible to quickly determine, without destroying the timber.
Hydrometers come in two types:
- needle - they are based on the measurement of electrical resistance;
- capacitive (contactless) - they are based on the relationship between the dielectric constant and humidity.These moisture meters have sensors that do not require the introduction of needles into the wood.Therefore, on the surface of the wood is left no trace after the measurement, which, of course, distinguishes them in this regard from the needle moisture meters.
meter nitrates
Nitrates - these are some of the chemical compounds that are the most dangerous because they can be a source of serious violations of the human body.Once the food in large quantities in the human body, they can cause nitrate poisoning, various chronic diseases and disorders.
once time-consuming and expensive process of detection of nitrates is currently implementing small special device - nitrate.
Nitratomers designed to measure in fruits, vegetables and fresh meat of nitrate.The basis of their work is the ion activity measuring electrode system direct potentiometric method, the results of which are converted into an electrical signal proportional to the concentration of NO3 ions.
to define and measure the nitrate product by piercing device has a special contact probe (probe).
Nitrate - digital instrument.Its dimensions are displayed in a convenient color display.
