Measuring instruments

Measuring instruments are one of the most important product families used in the laboratory. Determining temperature, density, pH, oximetry or other values with certainty determines the success of an analysis and its repeatability.

The best known are quantity measuring instruments such as cylinders, flasks or the more general scales. Other measurements are more specific and require instruments specialised in that function. This is the case of temperature with the thermometer or density with the densimeter.
Some values, however, are truly typical of the laboratory and are measured with devices whose name contains their usefulness.
The refractometer, of course, measures the refractive index of a substance while the spectrophotometer analyses the spectrum of visible light, from infrared to ultraviolet.

The most well-known are instruments for measuring quantities such as cylinders, flasks or the more general instruments of balances.

This is not, however, the case with burettes, which are glass instruments used to accurately measure the volume of a liquid. In this case, the name does not reveal the purpose, but it seems to derive from the French burette meaning small ampoule.

Electronic Measuring Instruments

Electronics is widely used in chemical laboratory analysis. Some instruments that until a few years ago were mechanical or manual now use advanced electronics for digital measurements.

pHmetres

This is the case with phmeters, for example, which are instruments that measure the ph of a liquid solution or sample.
The data is collected by a probe that is now electronic and sends the data collected to the instrument. The display and all its electronic functions are able to show the values and calculate them according to different units of measurement.
In addition, the probes are adapted to different uses, both for liquids and for solid and semi-solid materials.

Termometers

Another typical example of the application of electronics in a measuring instrument is that of thermometers.
Analogue instruments, which still exist, mainly use the mercury type.
These thermometers measure temperature by means of liquid mercury placed in a column that expands as the temperature rises.
With the advent of electronics, digital thermometers have become more widespread, partly because of the danger and difficulty of disposing of mercury.

Digital thermometers are also used for measuring temperature.

Digital thermometers detect temperature via a sensor consisting of a thermistor powered by electricity. The change in temperature has the effect of causing a change in electrical resistance in the sensor. This change, via an electronic circuit, is displayed on an electronic display in the form of a numerical value. The digital data can be easily displayed in different units and stored for statistical data collection.