The refractive index of a solution is strongly related to its concentration. Thus, you can get the concentration from the refractive index. Now, urine specific gravity is a common standard for assessing hydration status and sample validity testing. Refractometers can determine the specific gravity of urine by measuring the refractive index. So, this post will tell you about different types of urine refractometers and how to use a refractometer for urine specific gravity.

urine refractometer

What is urine specific gravity test

A urine specific gravity test is a common way to check your health and detect abnormalities. It compares the density of urine to the density of water, which will read 1.000.

By measuring the urine concentration, you can get the urine specific gravity. Then you will know your kidneys’ ability to balance water content and excrete products.

Thus, abnormal urine concentration may state some health conditions that change the body’s fluid status.

If your urine is too concentrated, your kidneys may not function properly or you didn’t drink enough water. And if it is insufficiently concentrated, you may have a diabetes insipidus. This results in a lot of diluted urine excretion.

urine specific gravity refractometer

What does a refractometer measure in urine

Urine specific gravity test is an effective and reliable method for checking abnormal changes in body fluid balance. And the common tool to detect the urine is a urine specific gravity refractometer.

Refractometers measure the degree to which light bends through a solution. So, they can help determine the concentration of the dissolved solids in a solution.

Some clinical refractometers measure urine specific gravity in seconds. Simply place a drop or two of the sample on the sample tank or glass and read the displayed value immediately.

Urine reagent strips can also measure urine specific gravity. However, urine refractometer is recognized as highly related to urine osmolality. And measuring urine specific gravity by refractometer is simple, fast, and accurate. So, it is a more technical tool for assessing hydration.

digital urine refractometer

How to calibrate a urine specific gravity refractometer

For manual urine refractometers, first open the cover and wipe the prism with a soft cloth. But for digital models, you just need to press the start key to initiate the device.

Then, place a few drops of distilled water in the sample tank or platform. Close the cover plate of manual urine refractometers. Because it aims to ensure that the water is evenly distributed.

Next, place the manual brix refractometer towards a light source. And then focus on the eyepiece. The blue and white boundary lines would coincide at a scale that will read 1.000. For digital urine refractometers, you don’t need a light source. After adding the sample, press the button and wait a few seconds to read the result. The reading would be zero in the end.

After the calibration, clean the sample tank or prism with a soft cloth. Ensure that there is no residue before measuring the urine sample.

digital urine refractometer

How to use a refractometer for urine specific gravity

It is necessary to check if the refractometer is after calibration. Before adding urine sample, remove water and dust on the sample tank or prism. Because it aims to avoid your sample becoming diluted that may impact specific gravity results.

First, place a few drops of the urine sample on the prism. Turn the prism of the refractometer at a light source and focus on the eyepiece. Then, read the specific gravity value on the scale. It is the concentration of the urine and refractive index of the sample.

As for a digital urine refractometer, the way it measures urine specific gravity is the same as you do other solutions. Take a small sample of the urine and cool it down to room temperature. Then, simply place a drop or two of liquid into the sample tank. Press the start key and you will get the specific gravity results within 2 seconds.

After the measurement, clean the refractometer with water if it is water resistant. And wipe the tank or prism with a soft cloth.

how to use a refractometer for urine specific gravity

Manual and digital urine refractometers

Manual clinical refractometers provide readings in about 1 minute. And the reading would be accurate if there is no user error. The errors may be poor calibration, not completely cleaning, and misreading the scale. But, a digital urine refractometer is the easier and faster tool for measuring urine. And the time required to read specific gravity results is a few seconds. This hand held refractometer is automatic in calibration, reading, and other operations. So it reduces the risk of some potential user errors like manual models.

Digital urine refractometers are becoming more and more popular. Because it comes with the fast readings and user-friendly design. The digital instrument only needs a small volume of samples for measurements. Besides, digital handheld refractometers are small-sized and battery-powered. So you can carry it around and apply it to field use. Also, digital displayed results would not have subjective interpretations like a manual model. And some digital urine refractometers may have automatic temperature compensation. Because it aims to ensure more accurate results. And the minimum scale of most digital refractometers may display up to the fourth decimal.

what does a refractometer measure in urine

The best urine refractometer

FJD digital refractometer is ideal for checking urine specific gravity in hydration measurements. This device is faster and easier to use than the manual urine specific gravity refractometer. And it is also more accurate than hydrometers and test strips. FJD refractometers can work as clinical handheld refractometers measuring urine specific gravity. Besides, this brix meter refractometer comes with digital displayed readings. And it is equipped with automatic temperature compensation. So, you don’t need to worry about the temperature changes that may reduce the accuracy.

In a word, the FJD refractometer comes with a wide brix range of 0-95%. Thus, it can measure almost everything you want including fruit, coffee, wine, honey, urine, etc. This tool can also work as a coffee refractometer, honey refractometer, and maple syrup refractometer. And it is easy to clean with distilled water as the IP67 water resistant characteristic. Besides, the minimum scale of this ATC refractometer can display up to the fourth decimal. If you want to have a digital tool that measures urine specific gravity, the FJD refractometer would definitely be an ideal choice.