How to use a blood alcohol meter correctly and how to choose one
A blood alcohol meter is a device for measuring the strength of alcohol. The most popular model looks like a long glass tube with a scale on it. There is a weight of shot, resin or mercury in the extended lower part.
How the alcohol meter works
The principle of measuring strength with a spirit meter is based on density and Archimedes' law. When the instrument is placed in the liquid, part of it is pushed out by the weight and reaches the division corresponding to the percentage of alcohol contained in the drink.
It should be borne in mind that an ordinary device (unless it is expensive professional equipment) works exclusively in water-alcohol mixtures, so it will not work for other products.
You can easily determine the strength of moonshine or vodka using such a tool, but it is not suitable for wine, liqueur, absinthe, liqueur, vermouth. A variety of impurities in the form of essential oils, juices and sugar affect the reliability of measurements downward, t. е. the recorded value will be lower than the real value.
What are the alcohol meters and which one to choose
A shot glass alcohol meter
A simple device for measuring the strength directly in a glass or shot glass, which should be used only for approximate readings. The error can be from 1 degree or more. The reliability of the data is highly questionable.
Laboratory (professional) alcohol meter
Meets the requirements of GOST and is the most respected among home producers of alcohol. Presented in different configurations. The most popular among moonshiners is the ASP-3, consisting of three devices for measuring different ranges of strength (from 0 to 100°). There are also more accurate models that include 11 and 18 instruments, but they are too much trouble. The best option for those who are fond of moonshining is the ASP-3 or ASP-T areometer (measures not only degree, but also temperature). Accuracy of readings - within 0.5 degrees.
Refractometer (optical alcohol meter)
The "coolest" alcohol meter with a minimum error, which is used in professional circles. Suitable for determining the strength of all alcoholic beverages, including wines, tinctures and liqueurs. But such a tool costs a lot of money, requires appropriate maintenance and adjustment, so it is usually not used at home.
Digital (electronic) alcohol meter
Instant response device that additionally determines the temperature. It is bought for measurements in the tank/cooler of a working unit during vacuum distillation. Not used for measuring the strength of the finished product.
Wine meter
Good for measuring the strength of the brew and sugar content in the wort. It is not suitable as a spirit meter, as it is limited to 25 degrees.
A home invention device
You can find many instructions on how to make your own areometers on the Internet, but the reliability of such products is unlikely to be high. They can be used only for fun or as a temporary replacement for a standard alcohol meter that has broken down.
How to use a breathalyzer
The most important thing to keep in mind when working with a blood alcohol meter is the need to control the temperature of the product and the environment. The standard for measurement is 20 °C. If possible, it should be followed, otherwise you should use a special correction table or our calculator.
The density of the drink is also affected by atmospheric pressure (although not so noticeably), if possible, it should be close to 760 mm Hg. st. st. The influence of other factors on the accuracy of the readings can be ignored.
To measure the strength, you need:
Pour the alcohol into a narrow glass container (about 100 ml). In principle, you can take measurements directly in the jar, but it is not very convenient.
Dip the alcohol meter into the drink, making sure that it floats freely in the liquid and does not touch the walls of the container. If the device sinks, you should take the option for greater strength, if it floats to the surface - for less (when it comes to ASP).
Wait until the fluctuations subside and take the reading. If necessary, adjust the value for the temperature.
When the device is immersed, a kind of funnel forms around it due to the tension of the liquid. To determine which line to measure (bottom or top), you should refer to the device's instructions.
If the temperature and other recommendations are strictly followed, the measurement error will be minimal.
Significant deviations are possible if the drink contains a lot of impurities or the device is dirty. The breathalyzer should be thoroughly wiped and washed before use. But this must be done delicately so as not to damage or break the fragile tool. For the same reason, it is better to store it in a box.
Update: 10.12.2019
Category: Vodka an Moonshine