The Hanna Checker 1 is a low cost, advanced pH tester with replaceable electrode. Range pH0.00 to 14.00 with 0.01pH resolution and ±0.2pH accuracy. Two point calibration at pH4/10 and pH7 using offset and slope screw trimmers. Powered by 2 x 1.4V (Duracell MP675H or equivalent) batteries giving up to 3000 hours operation. Supplied with screw-in, general purpose combination electrode and batteries.