I keep going back to it.

[Dennis Cartier]

I am in Europe. The last time I looked the UK still was.

Europe yes, E.U. no

I am not sure which countries this applies to, but I can say Germany is one, as I purchased 2 TM and 1 AquaMedic hydrometers, from German online vendors, and they all measured density and not specific gravity.

 

[atoll]

Europe yes, E.U. no

I am not sure which countries this applies to, but I can say Germany is one, as I purchased 2 TM and 1 AquaMedic hydrometers, from German online vendors, and they all measured density and not specific gravity.

Only German speaking countries apparently. Innthe UK and other countries we measure Specific Gravity.
The following is taken from the UK distributors site TMC.

Quite "Usually measured as specific gravity (also sometimes called relative density) and is one of the most important water parameters. Many tank inhabitants are sensitive to even minor changes of the water conditions. These should therefore be kept as constant as possible in the optimum range for each tank.

The specific gravity of natural seawater of 35 ‰ (psu) is 1.026 – compared to water measured at 25 °C / 77 °F. Our recommendation for aquarium water at 25 °C / 77 °F is 1.025 – 1.027 (depending on the tank type). For an exact, reliable measure of the specific gravity, we recommend to use the Tropic Marin® HIGH-PRECISION HYDROMETER.

Measuring and reading the specific gravity on the scale of the hydrometer will be easy with the new Tropic Marin® MEASURING CYLINDER. The high-quality plastic measuring cylinder is transparent, has a stable base and a spout. With a height of 36 cm (14 inches), it is ideally suited to determine the specific gravity using the Tropic Marin® HIGH PRECISION HYDROMETER. It is no longer necessary to switch off the flow pump for a measurement in the aquarium; just take the monitoring of the specific gravity outside of the tank. It is really simple!"

Photo of the scale on my TM hydrometer.

 

[Huey_Gnr]

Just ordered the TM hydrometer. I am eager to see what/if the differences are with my milwaukee refractometer and my instant ocean float gauge.

 

[Midrats]

Is there a good way to test the TM for accuracy? I guess I could mix up a gallon of salt water and test against that.

Reason I ask is I have had one for a while but questioned it's accuracy based on the paper in the stem. It just doesn't seem to be aligned right but I could be wrong.

View attachment 2988434

Observe the pic I posted earlier. The paper is in the same place as yours.

 

[JCOLE]

Observe the pic I posted earlier. The paper is in the same place as yours.

It doesn't appear to be. Notice the Tropic in yours is in the full stem. Mine is further down. The end of the paper sticks into the bottoms section. This is why I want to test.

I calibrated my Hanna and it was reading perfect 35ppt in the calibration solution. My tank water tested 36.6ppt after calibrating. The TM hydrometer was reading close to 38ppt.

 

[Midrats]

Maybe. Looks very similar.

 

[Dburr1014]

It doesn't appear to be. Notice the Tropic in yours is in the full stem. Mine is further down. The end of the paper sticks into the bottoms section. This is why I want to test.

I calibrated my Hanna and it was reading perfect 35ppt in the calibration solution. My tank water tested 36.6ppt after calibrating. The TM hydrometer was reading close to 38ppt.

View attachment 2990719

I would think manufactures calibrate by putting the paper where it reads correctly.
The glass, ball weights, ect., all may weigh slightly different in each one.

Other, "cheap hydrometers" I have read, that sometimes the paper slips. That is no good.
I have a feeling that the TM ones don't slip.
I have heard nothing but good reports from the TM ones.

 

[JCOLE]

Maybe. Looks very similar.

It does but the black end of the label in mine is in the bulb where yours is in the stem. I think I am going to pick up another one just to see.

 

[JCOLE]

I would think manufactures calibrate by putting the paper where it reads correctly.
The glass, ball weights, ect., all may weigh slightly different in each one.

Other, "cheap hydrometers" I have read, that sometimes the paper slips. That is no good.
I have a feeling that the TM ones don't slip.
I have heard nothing but good reports from the TM ones.

I am sure they do and I believe it was. I am thinking that maybe the paper moved. I will pick up another one to test against this one.