Beckman 72006 Expand-Mate Portable pH Meter w/ Probe Stand For Parts

Beckman 72006 Expand-Mate Portable pH Meter w/ Probe Stand For Parts

The Beckman Instruments 72006 Expand-Mate is a portable benchtop analog pH meter designed for measuring pH and millivolt (mV) values using a combination glass electrode. It features an expanded-scale analog meter movement for improved readability across the pH 0–14 range, a manual temperature compensation knob (0–100°C), and a multi-position function switch covering OFF, Standby, pH, pH EXP, and MV modes. This unit is being sold as-is for parts or repair due to two documented faults: the electrode probe has a broken tip, and the external AC power supply is not outputting any voltage.

Specifications & What's Included

• Manufacturer: Beckman Instruments, Inc. — Scientific Instruments Division, Irvine, CA
• Model: Expand-Mate
• Cat. No.: 72006
• Display: Expanded scale analog meter movement
• Measurement range: pH 0–14 (expanded scale); mV x100
• Function switch: OFF, Standby, pH, pH EXP, MV
• Temperature compensation: Manual rotary knob, 0–100°C
• Electrode input: BNC connector (side panel)
• Reference electrode port: Side panel
• Power: External AC adapter (included) and internal battery (BATT TEST position on meter)
• Probe stand: Included — adjustable clamp-style, mounts to top of meter body
• External AC power adapter: Included (not outputting voltage — faulty)
• Country of Manufacture: USA
• Known faults: Combination electrode probe tip is broken; external power supply is not outputting any voltage

Applications

The Beckman Expand-Mate series was a widely used line of portable pH meters produced by Beckman Instruments in the 1970s and 1980s, aimed at laboratory, field, and educational applications where a compact, self-contained pH measurement system was needed. These meters measured hydrogen ion activity (pH) and electrode potential (mV) using a combination glass/reference electrode, making them suitable for water quality testing, chemical processing, biological research, and general-purpose analytical chemistry. The expanded-scale analog display was a key feature at the time, providing finer resolution across a selected pH range compared to a standard compressed-scale meter. Beckman Instruments, a division of Beckman Coulter's predecessor, was a major manufacturer of analytical instruments for laboratory science through the mid-twentieth century, and the Expand-Mate remains recognizable to users of legacy lab equipment. This unit is useful as a parts source, donor instrument for restoration of a working Expand-Mate, or display piece.