Sper Scientific 850062 Test Tube pH Pens Tested Works
DescriptionFits standard test tubes 16 x 50 mm or larger.Highly stable and accurate readings with a large LCD display. Designed for simple one-hand operation. Automatically calibrates to pH 4, 7 and 10 buffers and can be adjusted to recognize some other non-standard buffers as well. Features hold function, and auto power off with low battery indicator.General PurposeGlass Probe: EPA compliant for labs and winePenetration Probe: for food & soilFlat Tip Probe: for meat, leather, paper, skin, and other surface pH measurements