Thanx for your reply Droopy.
That is what I meant as far as reading the concentration of NaOH with a pH meter. And the inaccuracy of such a procedure is what I suspected, though in practice, it does seem to be fairly feasible with a resolution of two decimals on a meter.
I don't make up solutions from crystals, namely because of what you stated about the hygroscopic properties, and partly because I don't trust my ability to weigh things that accurately. Instead, I purchase
1 N stock and dilute it down. Measuring volumes accurately seems fairly straight forward, though now I'm beginning to question the distilled water purchased locally. I standardize my solutions often due to the degradation characteristics of NaOH in solution plus the question mark surrounding the distilled water.
And finally, I'm not a homewinemaker. Not much beyond that, but do produce over 10k gallons professionally.
regards,
clyde
p.s. I use to post to this group frequently, and at that time there were other professionals here including many that where as qualified as professionals, but our ISP dropped the usenet account. Google use to be a hassle to use, but seems be acting well now!?