# Device for measuring density. Viscosity and fluid density

In factory laboratories, and in domesticsometimes it is necessary to use devices for measuring the density and viscosity of a liquid. These indicators have a significant impact on production processes. For example, to pick up a pump with a certain capacity for pumping oil, you need to know their viscosity. When drilling wells, an accident can occur if the corresponding mud density is not taken into account.

## Hydrometer

A hydrometer is a technical device for measuringdensity of a liquid. It consists of a glass bulb in which a glass tube is placed, which has a paper graduated scale. The flask is sealed on both sides, so there is a vacuum inside it.

At the bottom of the bulb is fixed ballastA substance that holds it in an upright position when immersed in a liquid. As a ballast, mercury or lead is usually used. Such a device for measuring density, like a hydrometer, operates according to the principle based on Archimedes' law. The force of ejection, which acts on a body immersed in a liquid, is equal to the weight of the fluid in the body's volume. A liquid substance having a different density pushes the instrument to the appropriate value, which is fixed on the scale of the device.

## How to use the hydrometer

The device for density measurement is not usedonly for technical measurements, but also for home use. A hydrometer can determine the alcohol content in wine or the concentration of sugar in the syrup.

The device is easy to operate. It is enough to lower it into a container with a liquid and note the division, with which the level of the surface of the liquid under test will coincide. The principle of hydrometer operation is the same in both industrial and domestic conditions. This simple device for measuring density has become quite widespread. They use it in the oil refining, chemical and dairy industries, as well as in medicine and at home.

## Checking the density of electrolyte

Many motorists are familiar with self-dischargebattery, when the electric circuit coming from the generator and providing battery charging, is perfectly in order. The problem, most likely, lies in the low density of the electrolyte. It is quite possible to do density testing yourself. The test should begin 6 hours after the last time the battery was charged. It is necessary to remember the acid contained in the banks of the battery, so you need to work in gloves. Before testing, open the caps on the jars, they are wrapped or tightly inserted into the holes.

The device for measuring the density of electrolyte works as follows:

1. Press on the "pear" and force out the air from the bulb.
2. Vertically lower the tip of the device into the electrolyte.
3. Release the "pear", the liquid enters the hydrometer, and the float will stop at a certain division. This is the value of the electrolyte density.
4. Verify the value on the device with the data of the data sheet or tester.
5. With a smaller value on the hydrometer than in the technical passport, a more saturated electrolyte solution should be added to the jar until the instrument readings increase to the required parameters.
6. Close the cover.
7. The battery is put on charge.

All the described actions should be repeated from the secondbattery bank. It should be noted that the device for measuring density should show the same values ​​in both banks or differ by no more than 0.01. The density of the electrolyte should always be at a certain level.

## Viscosity of liquid

In the liquid, the molecules of matter move along therelationship to each other under the influence of the external environment. When moving between molecules, friction occurs, which is called the viscosity of the substance. It can be of two types: kinematic and dynamic. Dynamic viscosity determines the fluidity of the fluid under real conditions, and the kinematic viscosity gives an indication of the fluidity of the liquid substance at various temperatures and pressures.

To measure the viscosity of a liquid,which is called a viscometer. There are a large number of methods and instruments with which you can measure the viscosity of a liquid. The most popular are ball, ultrasonic and rotary types of devices.

Which one to take viscometer for viscosity measurementfluid and how to determine it, depends on what kind of measurement accuracy and type of fluid being studied. Correctly to measure density and viscosity of a liquid - means, to make a qualitative product, to prevent accidents at work.