Hi Steve, The definition of the Seimen (mho) is the reciprocal of the Ohm. Therefore 1.0uS = 1MOhm and 10uS = 100KOhm.
Either your resistor is crook or you need to calibrate your unit. It cannot be the connection to the electrodes because the resistance is reading low. http://www.hannainst.com/products/testers/pwt.htm Water of 1.0uS from a home distiller is good, and your unit is reading high ;-) Might be wise to check each batch, as the output can vary. The voltage across the electrodes is AC of about 10KHz to limit the attraction of ions to either electrode. Should be fine if you don't leave it sitting in the solution. Just rinse in distilled water when done. Ivan. ----- Original Message ----- From: "Steve Young" <[email protected]> To: "Silver List" <[email protected]> Sent: Thursday, 22 June 2000 15:36 Subject: CS>PWT Calibration Hi list, 1) I bought a Hanna PWT, model HI 98308. As an electronics engineer, of course I had to take it apart to see the "guts". Very nice instrument! I am surprised they don't cost more. A previous post by someone indicated his PWT could be calibrated with a precision resistor. for his model, 100K Ohm = 10 uS and 1 Meg = 1 uS. But with mine, 100K indicated 16.2uS. Obviously, there must be some difference in the electronics and/or electrode geometry between mine and his. Can someone tell me what value of calibration resistor the HI 98308 needs to read 10.0 uS? Or for a given reference resistance, what my PWT meter should read? 2) My distilled water reads 1.0 uS. Source is a neighbor's commercial steam distillation unit. Is that about as good as one could hope for without a lot of additional effort or expense? 3) When measuring CS with a PWT, how does one keep the electrode chamber from gradually getting silver in it which will affect the readings? Seems like the only easy way to clean it is to swish it around in some distilled water, or maybe use a water pik to squirt DW into the little electrode openings. Thanks, Steve Young -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
