# Are portable pen pH-meters accurate?

Are pen $$\mathrm{pH}$$-meters accurate? I know there are large table-top $$\mathrm{pH}$$-meters, but I keep seeing these small $$\mathrm{pH}$$-meters online that can read up to 0.1 units. My question is if these $$\mathrm{pH}$$-meters (look pretty cheap) are accurate or should I get the large table-top $$\mathrm{pH}$$-meter for my experiment (will need accuracy minimum of 1 decimal place).

(Edit: Is there also a minimum volume of sample I need before I can test it with a $$\mathrm{pH}$$-meter?)

• I would say that it's too broad. Could you ask about a specific pH meter? Quality could vary across region, price and make.. – William R. Ebenezer Jul 3 at 13:47
• I'd say they are as cheap as they look. But then again, a table-top pH-meter can also be wildly off unless you maintain it properly. – Ivan Neretin Jul 3 at 13:49
• I've decided to get portable pH meter for 'Hanna Instruments' (hannainst.in/waterproof-portable-ph-meter-hi991001p.html) . It does seem like a reputable company with a quality product, compared to all the other pH meters I've seen online in the market. – TheTenthBox Jul 3 at 13:58
• Several well known instrumentation/measurement companies offer small hand-held pH meters with specified pH resolution of 0.01 - I see no reason to doubt that they fulfill those specifications. – Jon Custer Jul 3 at 14:03
• I see. Thank you all for your inputs. – TheTenthBox Jul 3 at 14:12