Self contained pH meter with wooden exterior; hinged lid opens to reveal meter face and inlaid paper instructions for use; the dial is calibrated from pH 0 to pH 13 in .1 pH divisions; porcelain enamel lined electrode compartment at front of pH meter; hinged wooden door opens to reveal compartment when instrument lid is open; no electrodes; key to the unit attached by a cord to the handle.

Designed for precise measurements in the laboratory but also suitable for field and factory use. With combination pH and millivolt scale, permitting both pH determinations and oxidation-reduction potential measurements, new type glass and calomel electrodes and lock-down switch. Portable, self-contained, direct reading instrument suitable for practically all substances.