Refractometer P-RHA-503ATC. A useful device when preparing a car for winter frosts.

To briefly describe the need for this device, we can quote one of the classics of the literature of the past:
Once in the cold winter season I left the house,
pepelats did not start and left back .. Winter is not over yet, so welcome to kat ->
Winter is a crucial time for the car owner, since it is in winter that all the nuances that are simply not paid attention to in mild conditions in warm time are manifested. But with the advent of winter, careless motoriststhey encounter a frozen washer, a bursting engine, and an iron friend who can only blink an emergency gang ... And the wife standing nearby asks sternly when will you start to bring hot cakes to her mother before they cool ...
Looks like I went too far with imagination.
Well, ok, let's go by describing our own experience. My iron horse immediately after the purchase was driven into the service station, which was advised by an old friend, as he had previously worked for it. After carrying out the complex of work necessary to calm his morale, he drove to his new place of work, to the officials of one of the famous American car brands, for a couple of spare parts, and at the same time to show him a super-mega-wah device for checking freezing temperatures which they have. The device showed that the locksmiths from the first service station needed to tear off their hands and stick them ... hmm ... More precisely, he showed the freezing temperature of antifreeze at -10 centigrade. This is at the beginning of December. And in winter we have -25 at least a week, but it happens. It was the day I found out what a refractometer is.
A bit of a dry, uninteresting theory

And now in plain language:

Light passing through the test substancedeviated by a certain angle, and on a scale graduated depending on the required concentration / properties, the parameters of the analyte are determined.
A car refractometer allows with prettydetermine with high accuracy the freezing temperature of antifreeze (brake fluid) based on ethylene glycol and propylene glycol, as well as the temperature of liquids poured into the wiper tank, in addition, reflectometers are able to determine the electrolyte density in batteries (battery charge state). In fact, the refractometer measures the optical characteristics of antifreeze and other coolants - the refractive index associated with the degree of dilution of the antifreeze concentrate with distilled or ordinary water and its crystallization temperature. Since a car refractometer is a more accurate instrument than a hydrometer (such a transparent crap, working on the principle of a float, in which the scale constantly falls out of its place, because the accuracy is about a finger in the sky), its accuracy characteristics for determining the crystallization temperature of antifreeze can already be ± 1 ° FROM. At the time of use of the refractometer, certain rules and precautions should be observed. Carry out measurements at liquid temperature strictly plus 20 ° С. Use the table of conversion of refractive indices into the crystallization temperature of the coolant for a specific brand of antifreeze. If a portable automobile refractometer has a measuring scale set in degrees Celsius, it must be taken into account that this scale is adapted to a specific antifreeze, most likely to a mixture of ethylene glycol and water. Such a device for measuring the temperature of non-freezing liquids can only serve to estimate the temperature of crystallization onset.
With the theory finished, go to the device itself. The device arrived in a cardboard box wrapped in a little bubble, and was not damaged by mail. On the box there is a sticker with the model, inside the box there is a manual sheet in English, with double-sided printing, the device in a bag, 10 plastic pipettes and a screwdriver. The overall dimensions of the refractometer itself are 154 * 40 (eyepiece) mm, weight 76 grams.

The eyepiece rotates to changediopter. also, the device spins approximately in the center, and a scale is visible that is rigidly fixed relative to the refracting part of the device. I did not begin to disassemble further, so as not to knock down the setting.

Using the device is very simple. It is necessary to look through the peephole. and in the eye we see such beauty:

which so far says little to us. The visible scale starts from the “WATERLINE” line, well, let's check. We take a drop of water (I had it after the usual kitchen, such as a jug), drip onto the work surface and close it with a matte plate.

This test shows that the OTDR does not lie on water, it really freezes around 0 centigrade.
The last time I tested antifreeze before winter,it showed about -50 photos then did not, and now laziness (for that)). And now the most delicious. Battery and his love of Epiphany frost. What happened to me is what I allegorically described with the words of a classic. I did not help even a lint feint from a spare battery. More precisely, on the third day of frosts, even a spare battery paired with the main one could not start the car, so we went to the pancakes to my mother-in-law by taxi, putting the battery on charge. After a day on the charge, the electrolyte density was shown at 1.25-1.26 Kg / l (Kg / cm * 3), the starter twisted vigorously, just like a young one (the battery went 3rd year), the car started up easily, but at a temperature overboard about -28 and a speed of 80km / h, the windshield froze from the headwind, although the stove was steaming at full speed, but this is a diesel and a completely different story ..))
Back to the spare battery.
!!! WARNING !!!!
There is acid (solution) in the battery, be careful !!! in case of contact with skin - rinse with plenty of water, protect from contact with eyes
At the time of its verification, the main one was already removed fromcharging. The spare (over 10 years old) in the dead state had the lowest rate of 1.21, we charge about a day, and we begin to check, the results are in the table.

When charging the battery, I was guided by the table below, which, as it turned out, corresponds to the “GOOD” zone on the refractometer scale.

The result is simple - a must have)), especially if you climb under the hood yourself and know what is there and why.
In Ali, other sellers have cheaper and immediately in a plastic case, which is more convenient. Took a long time, the price is now lower.