Cricket (Newbee)
01-17-03 17:19
No 399238
      Differences in pH Meters.  Bookmark   

SwiC is looking at some pH meters and can't seem to find much info on a particular brand/model.

If the name is unexceptable, SwiC understands the mark out. The brand is Chekmite, and he can't find any specs on these:

Chekmite pH Testers
(WLS-30018-01), 1 pH Meter
(WLS-30018-03), 3 pH Meter

or maybe someone realizes the differences and can share their insight. Swic as never bought one before and knows little about them. Any help is greatly appreciated.

Thanks a bunch,
C.

If it ain't clean, it ain't my scene!
 
 
 
 
    lugh
(Moderator)
01-17-03 18:05
No 399250
      pH meters are unreliable for our purposes  Bookmark   

Don't waste your money on pH meters, they're unreliable and inaccurate frown Here's some applicable threads for you to read laugh
Post 313062 (krystalle: "rookie question..........", Chemicals & Equipment)
Post 291348 (pseudaus: "ph paper maddness??!!", Newbee Forum)
Post 277059 (Rocksolid: "PH indicator", Newbee Forum)
Post 182127 (Synthia: "ph meter", Stimulants)
Post 83672 (noj: "digital ph-meter (cheap)", Chemicals & Equipment)
Post 80251 (ANONYM: "pH meter problems", Chemistry Discourse)
Post 55160 (SuperAssman: "Diluting NaOh &Ph Go Up?", Stimulants)
Post 44595 (Jacked: "Re: pH-Tester", General Discourse)
Post 15808 (speedygonzaless: "ph paper in oz", Newbee Forum)
Post 7331 (XplosiveKemistry: "Ph tester", Newbee Forum)
Post 97314 (DroYd: "Damn PH gauge,..........^^^I Hate Them^^^.........", Chemicals & Equipment)
Post 84245 (ero323: "iso or no?  pH paper ok?", General Discourse)
Post 123038 (DeJay: "PH paper", Newbee Forum)
Post 109642 (not existing)
Post 104537 (dr.fart: "REALLY Stupid Question", Chemistry Discourse)
Post 100563 (Commodium: "pH Meters, How Often to Calibrate?", Chemistry Discourse)
 
 
 
 
    JoeCool25
(Hive Bee)
01-17-03 19:02
No 399265
      Question about HCl titration at the end.....  Bookmark   

Don't waste your money on pH meters, they're unreliable and inaccurate.....

Lugh, Question about HCl titration at the end, is it there not better to have a ph meter, with the always changeing ph? (perhaps to go from 13 to 5,5 ?)
Swim know that often to get to 7 it takes very much more hcl and after 7 to 6 and 5 it goes very fast.
With ph-paper swim must be very carefull not to overshoot.
Swims ph-meter (old) is broken. Swim thinks to buy a new one.
Now swim read that itīs make no sense to use one.

Is this correct for hcl titrations too ?

Thanks for every Info. /Joe.
 
 
 
 
    lugh
(Moderator)
01-17-03 19:21
No 399270
      titration  Bookmark   

Titration is best done using only half of the free base, that way when you overshoot you can recover smile Cheap pH meters don't work with non aqueous solvents, and often quit working at the most inconvenient time frown