Draper anti freeze tester - Completely useless?

[dunc_sx]

User error?

I bought one of these today, no other brands were available elsewhere due to the time of the year so had to get the draper It's to test the coolant on a new to me car I've just taken delivery of, my previous tester has gone AWOL.

https://www.drapertools.com/product/01053/Anti-Fre...

I tested the car in question and it read -12 degC. I then tested straight water, again -12degC. I then tested my race car which has fresh 50/50 coolant, -17degC (retested and -12degC)

I then realised by adjusting the size of water sample you can get it to read almost anything you want (all the time the float is neither touching the top or bottom).

I'm returning it tomorrow and hopefully the shop can show me what I'm doing wrong, but if not I'm fairly sure that's a clean sweep of every Draper tool I've bought being returned. How are they even in business? Perhaps I'm unlucky.

But on the bright side at least my coolant's freezing point isn't any worse than water

Dunc.

[GreenV8S]

I suspect you're using it wrongly. That type should be consistent and repeatable, even if they aren't accurate. Are you allowing the float to touch the sides? If so, it won't work. Also, you need to make sure there are no bubbles attached to the float.

Edited by GreenV8S on Wednesday 4th December 18:33

[SAS Tom]

I find sometimes everything rises and you have to wait a minute or two for it to settle.

[227bhp]

Said the actress to the bishop.

[dunc_sx]

Thanks for the suggestions, it's 100 percent not possible to avoid the float touching the sides. It's off balance so can't stay clear of the casing. The bottom touches one side and the top touches the other, regardless of how you to tilt it this cannot be avoided.

I've tried leaving it for up to 5 mins, no joy.

Every single one similar I've used it's just a case of filling with fluid and reading though, so unless something changes drastically it'll still be getting returned. As stated above in lieu of accuracy it should at least be repeatable.

Dunc.

Edited by dunc_sx on Wednesday 4th December 21:58

[GreenV8S]

dunc_sx said:

it's 100 percent not possible to avoid the float touching the sides. It's off balance so can't stay clear of the casing. The bottom touches one side and the top touches the other, regardless of how you to tilt it this cannot be avoided.

In that case it's broken. It's fundamental to the design that the float mustn't touch anything.

[paintman]

All the testers of that style I've used have been the gizmo - balls or a float - in a glass tube variety that you suck liquid up into.
None have had any sort of mechanism that stops the gizmo touching the glass.

Get yourself a refractometer. Much better.
This youtube worth a watch, pretty thorough 'how to': https://www.youtube.com/watch?v=I6TtAMg_Lzk
The type she's using are less than a tenner on ebay.

[julianm]

If you're still concerned about the possibility of it freezing pop a sample of it in an eggcup & leave overnight in your freezer. Most seem to run at -18 so if it's still liquid I reckon you're Ok in most of Britain.

[GreenV8S]

paintman said:

All the testers of that style I've used have been the gizmo - balls or a float - in a glass tube variety that you suck liquid up into.
None have had any sort of mechanism that stops the gizmo touching the glass.

Hopefully none of those would have had a float that was trying to fall over and being held upright by the glass.