The Model 3505  pH Meter is one of three benchtop laboratory pH Meters available. At the lower end of specifications and price of the three laboratory pH Meters, it can measure between 0 and 16.00pH, -1999 and +1999mV, and -10 to 105ºC. Power is supplied by a 9V MN1604 battery Readings are displayed on a 25mm 7 segment Liquid Crystal Display.

The Model 3510 pH Meter is the mid-range benchtop laboratory pH Meter. Measuring between -2 and 19.999pH, -1999 and +1999mV, -10 and +105ºC, and +14 to +225ºF, it can store up to 32 readings. Temperature compensation is automatic between 0 and 100ºC, and calibration is user selectable 1, 2 or 3 point. The Model 3510 pH Meter is powered by  a 9V AC Power Supply Unit.

The Model 3520 pH meter is the top-range benchtop laboratory pH meter offered. With a reading range the same as the Model 3510 pH Meter detailed above, the Model 3520 pH Meter contains a 24 hour clock for accurate time stamping of readings. To ensure Good Laboratory Practice, a calibration reminder facility can be set with an interval of between 1 and 999 hours from last calibration. A timed print facility can also be initiated with an interval ranging between 1 second to 1 day.