[Jeff1]

Hi to all members.
I'm new to the forum and the world of chemistry.
Now this is going to be the most weirdest post you people have ever had on this forum, so please bare with me.

By Trade I'm a window Cleaner, not the type that climbs ladders as H&S is slowly putting more and more restrictions on ladder users, so now many window cleaners are changing to use the telescopic pole method where pure water is pumped up to the brush, the windows and frames are washed and left to dry naturally as you know the water contains no impurity's so doesn't dry spotty.

We produce are own pure water from tap water with reverse osmosis and deionised resin to bring the TDS reading down to 000tds, we use TDS meters to check the water.

I have just found out that we need to recalibrate our meters at least once a week with 342 ppm Na Cl solution, although this solution is available commercially at £5 per bottle, the bottle being the size of an egg cup.
I would love to make my own so this is my reason for posting on your forum.
Can any one tell me in plain English (don't forget I'm a window cleaner lol) Can I make this solution and at 342 ppm  from items easily available.

Thank you in advance for all your kind help and for being gentle with me Lol

[AWK]

Dissolve 342 miligrams of pure NaCl in 1 liter of distilled water.

You use also 343 ppm in your post?

[Jeff1]

Dissolve 342 miligrams of pure NaCl in 1 liter of distilled water.

You use also 343 ppm in your post?

Thank you AWK for a speedy reply
Any idea where I can buy pure NaCI and is it legal to purchase? I don't want to be breaking any laws.

Thank you for the correction

[Borek]

I believe kitchen salt (which is basically NaCl) is pure enough for your purposes. Just look for teh white one, not a sea salt, or microelement salt or whatever.

I am in Poland, no idea how kitchen salt market in US looks alike.

[Arkcon]

Chemically pure sodium chloride is easily purchased by someone with a corporate mailing address.  It may be a little more pricey than supermarket brand table salt, but will be much purer.

The problem is the actual concentration will only be as good as the purity of your reagents -- the salt and the water to dissolve it, and your skill in careful measuring, mass of salt and volume of water.  The company selling you this high priced egg of magic juice is charging you a premium, but they guarantee their product.  Think carefully if you really want to go the DIY route. 

[Jeff1]

Chemically pure sodium chloride is easily purchased by someone with a corporate mailing address.  It may be a little more pricey than supermarket brand table salt, but will be much purer.

The problem is the actual concentration will only be as good as the purity of your reagents -- the salt and the water to dissolve it, and your skill in careful measuring, mass of salt and volume of water.  The company selling you this high priced egg of magic juice is charging you a premium, but they guarantee their product.  Think carefully if you really want to go the DIY route. 

Thank you all so much for your helpfull replies, I even gave you all a scooby snack.
I will try the diy route and I don't mind paying the extra for the pure sodium chloride, I have a tolerance of  5%+- to play with, I also have a couple of TDS meters and a manufactured bottle of calibration fluid to go by, making my self up 1ltr will last a long time, so well worth the time and effort.

Once again guy's you all very kind and helpfull.

[Arkcon]

Good job in your last post.  You know your allowable tolerances, and you've decided to keep a commercial standard around for comparison.  You've done more good stuff here than some of the pros on this board.  Scooby snacks back at 'cha.

[Jeff1]

Thanks for the compliment, the thing is, is my TDS meter has to be spot on, if its not this will affect the end result for my customer, no being there my bread and butter  I have to get this one right.

I have ordered a bag of Chemically pure sodium chloride, just waiting for its delivery.

Thanks for the scooby one back to you for the compliment.