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UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Moderator David@stives on September 28, 2005, 10:56:22 am

Title: Tds metre help
Post by: Moderator David@stives on September 28, 2005, 10:56:22 am
how do you use the hm digital hand held tds metre.it is the same one sold nationally like wintecs etc

do you fully submerge the metal prongs or do you just put them half way  under the water

my tds reading is

38 half way under

70 fully submerged

Dave
Title: Re: Tds metre help
Post by: Philip Hanson on September 28, 2005, 11:35:24 am
Fully Submerged.

TDS meters measure the conductivity between the two prongs, the more dissolved solids in the water, the more it will conduct (as it is the dissolved solids that conduct the current)

They are callibrated on the basis that the prongs are fully submerged.

A reading of 70 eh?  Thats soft, do you bother with RO?

-Philip
Title: Re: Tds metre help
Post by: Moderator David@stives on September 28, 2005, 11:39:46 am
thanks

no ro at all just 18 litre vessel .i have used at least 5000 litres so far and still getting 0 tds
Title: Re: Tds metre help
Post by: dai on September 28, 2005, 09:47:48 pm
Just done my whole round for the first time WFP tops only. Still getting 0 TDS from my 8ltr DI cyllinder. I carry a class for taking TDS readings with 1 1/2 inches of water in it.
My tap water comes out at 57. If I can get 3 months out of a bag of resin I may just stick with DI. I filled a larger DI vessel today, one of those e-bay ones. the water out was 0 TDS as you'd expect, but I noticed a fine film of resin on the top of the water in the containers. Is it normal to have a fine film of resin after a new fill?
I know the strainers are positioned correctly but don't think the composit vessels were used with DI resin before. Maybe the strainers arn't fine enough. I am talking about a very fine film of resin though. Dai
Title: Re: Tds metre help
Post by: Moderator David@stives on September 28, 2005, 09:54:54 pm
that will soon flush away

Dave
Title: Re: Tds metre help
Post by: rosskesava on September 28, 2005, 11:00:28 pm
Quote
My tap water comes out at 57

My tap water yesterday was just over 300.

I've just done a tds reading with the prongs half submerged and fully submerged and the reading do differ.

Quote
They are callibrated on the basis that the prongs are fully submerged.

Just goes to show how important it is to read the instructions doesn't it.

Quote
the water out was 0 TDS as you'd expect

Zero??? We've got a 100gpd with 2 di catridges and the best we get is between 7 and 15. The lower the tap water (which seems to go up and down over a few days) the lower the tds in the barrel.

Cheers