 The original pH meter weighed in at nearly 7 kg, but was a substantial improvement over a benchful of delicate equipment.The earliest meter had a design glitch, in that the pH readings changed with the depth of immersion of the electrodes, but Beckman fixed the problem by sealing the glass bulb of the electrode.On April 8, 1935, Beckman renamed his company National Technical Laboratories, formally acknowledging his new focus on the making of scientific instruments.