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UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Ian Lancaster on November 13, 2008, 07:24:42 pm

Title: How accurate is your TDS meter?
Post by: Ian Lancaster on November 13, 2008, 07:24:42 pm
Some lamebrain got into my van a few weeks ago and stole: all my invoices, my lunchbox with one sandwich in it, my service record book for the van, and my TDS meter (hand held).

Apart from the fact that it must have been a particularly backward retard (what the hell was he/she going to do with that lot, especially as he/she wouldn't have had the foggiest what a TDS was for) it meant I had to invest in a new lunchbox and TDS meter, as well as print up a load of new invoices.

From the start the new TDS meter showed a reading of 002, even though I've got a pretty new pumped 40-40 system followed by a big DI cylinder with new resin in it.  After a week or two the reading went up to 004.  Being a bit suspicious I bought a bottle of calibration fluid, guaranteed TDS 342.  My meter showed a reading of 395, a discrepancy of 13.42%

I've had a look and I can't see any way to adjust it, though I've e-mailed the supplier for advice.

Anyway, the point is:

Do you trust your TDS meter, and if so why?

Would you trust calibration fluid to be what it says on the bottle, i.e. 342 ppm?
Title: Re: How accurate is your TDS meter?
Post by: Chris Galloway on November 13, 2008, 07:29:55 pm
I would hope my tds meter was calibrated properly at the manufacture stage. But if you cant trust calibration fluid who the heck are you gonna trust!?
Title: Re: How accurate is your TDS meter?
Post by: alanwilson on November 13, 2008, 07:45:04 pm
Ian

Calibration fluid is EXACTLY what it says, if it says 342ppm then that is what it is as it is used to calibrate with (its all made from standard soln)

Look on the back of the meter, there should be a small hole somewhere near the to of the unit - behind it is a small screw, adjust that screw until the reading says 342 (obviously while in the soln)
Title: Re: How accurate is your TDS meter?
Post by: elite mike on November 13, 2008, 08:27:16 pm
hi ian
i have ro man in line tds meter and pure freedom hand held

both show different readings :o

do i trust them   no >:(

i have cleaned with readings of 15 tds with no probs 8)

mike
Title: Re: How accurate is your TDS meter?
Post by: Captain Scarlet on November 13, 2008, 08:30:10 pm
Ian, most meters can be adjusted with a screw driver, i believe behind the batteries.
Title: Re: How accurate is your TDS meter?
Post by: dai on November 14, 2008, 04:29:45 pm
I don't use resin when the meter gives a reading of 002, well I do but only in the first in line vessel.
I trust the meter because I have always had perfect results with it. Irrespective of what the true reading may be, I know I will get good results below 002.
Title: Re: How accurate is your TDS meter?
Post by: Slash on November 14, 2008, 04:35:49 pm
I have two handheld tds and both are different readings! :o
Title: Re: How accurate is your TDS meter?
Post by: matt on November 14, 2008, 04:41:08 pm
as long as its below 010 no issues
Title: Re: How accurate is your TDS meter?
Post by: mci services on November 14, 2008, 08:53:55 pm
where do you buy calibration fluid and how much does it cost
Title: Re: How accurate is your TDS meter?
Post by: jouk45 on November 15, 2008, 09:27:55 am
where do you buy calibration fluid and how much does it cost
you can buy it from ro man stu.
http://www.ro-man.com/shop/product_info.php/cPath/29_81/products_id/133
Title: Re: How accurate is your TDS meter?
Post by: mci services on November 15, 2008, 08:24:13 pm
where do you buy calibration fluid and how much does it cost
you can buy it from ro man stu.
http://www.ro-man.com/shop/product_info.php/cPath/29_81/products_id/133
thanks jouk