How to test concentration of CH protector

[Marnhullman]

Hi

I've just added some Fernox Superconcentrate to my pressurised system -I don't know if there was any in the system to start with so now it should be OK. However, when and how do I test the concentration in future?

From what I can gather one tube of Fernox should treat 10 rads, we've got 19 rads so I used 2 tubes. Could I get away with adding one tube a year to keep the system topped up or do I have to invest in a TDS meter? I'd rather not due to cost and the infrequency of use. If I do need a meter are they easy to use and which is the cheapes that'd do the job?

Thanks

 

[ChrisR]

One tube evry 5 years should be fine unless you're losing water.

Cheap good test is with a nail.
Drain off some water (radvent would do) into a small jar.
get a nail, cleaned well, with sandpaper say, and pop it in, and leave it. If you get rust inside a week, time for more jizzm.

TDS meter wouldn't help you, but you can buy test kits from Fernox.

 

[bengasman]

Bit of steelwool in jam jar with water from radiator and the top firmly back on will simulate effectively what is going on in your system. Same idea as the nail, but much quicker.
Or, if in doubt, add another dose now and forget about the whole thing for years. 20 quid to erase doubt about protection of your system sounds like a good investment to me. comes to 1 penny a day for the duration, not worth the effort of testing, let alone the cost.

 

[Onetap]

Bit of steelwool in jam jar with water from radiator and the top firmly back on will simulate effectively what is going on in your system.

That doesn't work, nor does the nail test.

One cause of corrosion is dissolved oxygen; removing the water from the system will allow it to dissolve oxygen from the atmosphere, giving a false indication of corrosion rates in the system.

Another cause is galvanic corrosion, which happens as a result of copper and steel being in contact with a suitable electrolyte. A bit of steel in some of the water won't indicate what is happening to steel in contact with copper pipes.

The only sure test is a test kit. Fernox etc., won't tell anyone what the active ingredients are, so you have to buy their overpriced kit.

 

[Marnhullman]

Thanks to all. Since I've just added concentrate and am not losing water I'll leave for the forseeable future. If I need to add water I'll maybe add some more concentrate in a year or so.

Regards