Good. I saw some for $50-$100 & thought that was kinda out there.Even the cheapies on fleabay are reasonably accurate if you calibrate it properly and store it according to instructions.
No intrusion.....good question.Don't mean to intrude on the thread, but how about TDS pens as well? Are the cheapest ones on ebay or amazon reasonably accurate?
I bought a TDS pen a couple of months ago......wishing now I had bought the ph/TDS combo.Yeah, you even get a multifunction one that does both pH and TDS, doubt it will even cost you $15.
Don't even think mine took 10 working days from hong kong.