Antifreeze Refractometer 4-in-1 Coolant Tester Refractometer for Checking Freezing Point of Automobile Antifreeze Systems, Anti Freeze Tester Refractometer for Battery Acid, Ethylene Propylene Glycol

I was originally apprehensive about using this type of refractometer, having only used the "floating balls" type before.However, the included instructions are clear and show how to calibrate and read it. Frankly, it looks a whole lot cooler to put a drop on the slide, close the cover and look through the eyepiece, announcing your findings like Mr. Scientist than it does to see how many balls are floating in a modified turkey baster. It's also more accurate as it gives a specific reading instead of a range.Impress your friends or significant other! Feel like you're back in a chemistry class. Or feel like you're in a chemistry class for the first time if you've never been in one before.It seems like a good product, it comes in a case with instructions and a tool for calibration (you will have to supply your own distilled water to calibrate it.) Once calibrated, it seems to maintain the calibration for quite a while. I did not have to make an initial calibration and it hasn't drifted from it yet.

Bought 2 of these to use to test propylene glycol antifreeze concentration, They appear to be well made and should work for us.

I bought 2 of these. One is for my son. One came damaged and is going to be exchanged. The instruction booklet say nothing about the scales or how to read them. As another review mentioned, the pictures don't correspond with the calibration instructions. My primary need is for testing DEF for my RV. I read on a forum that some nasty soles like to buy DEF at Walmart and return the container filled with water. This will do major damage to the DEF system of the unlucky person who gets stuck with it. I don't want to be that person.The replacement instrument came today. I bought some distilled water and checked the calibration of each. Both are set to zero upon arrival.One word of caution. Make certain the test area is saturated under the window. No air gaps. I had to hold the test area level to get the drops to disperse correctly and fill the test area.Seems like a well made tool/fragile instrument.

This refractometer has proven to be a critical asset for maintaining my off-grid solar system batteries. If you are similarly inclined YOU MUST GET THIS DEVICE.I used to fiddle and futz with the “turkey baster” type of hydrometer. I was constantly fighting air bubbles, the float would stick to the side of the barrel... etc. My readings were little more useful than just a basic “go/no-go” reflection of charge. Accurate and quantifiable readings were basically impossible.With this refractometer, the game has now completely changed. With just a drop of battery electrolyte, I can make repeatable measurements of + or - 0.001 SG units. This at least 10x better than the old “turkey baster” hydrometer could do on a perfect day.The real eye-opener was discovering that my charger equalization settings were almost totally wrong. After an equalization charge, the cells were not within the target SG range relative to each other. With this refractometer, I was able to quickly optimize the charger voltage/current/time settings. Now I get almost perfect results.Bottom line: get one. You need it. It will be the best $20 you can spend to keep your batteries healthy.

I've never used one of these before and I was afraid that it being a good price it would be cheap. It is well made, has a nice plastic case, an included screwdriver to adjust it, and a microfiber wipe to clean the glass plate. Right out of the box it was lined up perfectly using distilled water. It was absolutely accurate and I'm glad I made this purchase.

Tried the test strips but found they were very vague in their testing. This tool quickly gave me a precise, no doubt reading of the antifreeze level in my boiler system. Good value and accuracy.

I am an HVAC contractor and have a few refractometers which we use primarily to measure propylene glycol antifreeze solutions. Bought this as a replacement for one of my units that was dropped and destroyed. This unit came calibrated and seemed just fine .... until we used it to take a few measurements. All concentrations that were measured all tested out to 5 degrees Fahrenheit. Even the straight propylene measured 5 degrees. We checked the readings with two "proven" refractometers and while the two units agreed across the scale, this unit consistently read 5 degrees Fahrenheit. Sending it back.

As is typically the case with "precision instruments" from that part of the world, the attention to detail is always lacking.In this situation, the instructions utilize the same graphic for every instruction indicating that when calibrating with distilled water, (a bad idea anyway) the image for "calibrating to 0" (attached here) is not at "zero". When calibrating with distilled water, the calibrated setting should be at the "waterline" mark.Has to leave one wondering about how much care was put into the rest of the product.