CORNING LABORATORY Analytical Ph Meter 245 Digital M245

Circa Early 1990's

A general-purpose digital bench-top instrument designed for precise measurements of hydrogen ion activity in aqueous solutions.It acts as the central processing and display unit (the "meter") but requires several external components to perform measurements.

Required Accessories:

To function correctly, the following accessories are necessary:

• pH Electrode (Probe): The most critical accessory. It plugs into the back of the unit (typically via a BNC connector) and is submerged in the sample to detect hydrogen ion activity. A common compatible probe is the CORNING 476530.

• Calibration Buffer Solutions: Standardized liquids with known pH values (usually pH 4.01, 7.00, and 10.01) used to calibrate the meter before each use to ensure accuracy.

• Distilled or Deionized Water: Used to rinse the electrode between measurements to prevent cross-contamination of samples.

• Power Adapter: Most units require a 120V AC adapter for laboratory bench-top power.

Optional Accessories:

• Temperature Probe (ATC): While pH can be entered manually, an Automatic Temperature Compensation (ATC) probe allows the meter to automatically adjust readings based on the sample's temperature.

• Electrode Stand/Arm: A weighted base with a flexible arm to hold the fragile glass electrode securely at the proper depth in your sample beaker.

• Magnetic Stirrer: Often used during measurement to ensure a homogenous sample, which helps achieve a stable reading more quickly.

Use Cases:

• Scientific & Industrial Labs: Used for chemical analysis, biotechnology, and monitoring reaction conditions.

• Pharmaceutical & Biotech: Vital for drug development, formulating compounds, and ensuring product quality.

• Educational Institutions: Often found in university hospitals and academic research settings for routine testing.

• Environmental & Field Analysis: Suitable for water analysis in agriculture and industrial processes.

Historical Significance:

CORNING pH meters, like the 245, were part of the transition from analog "acidimeters" to digital laboratory standards. They integrated electronic technology into a rugged, "all-in-one" design, allowing scientists to move beyond subjective color-change indicators to achieve highly precise, quantitative numerical values. This model represents the "workhorse" era of digital lab equipment that democratized accurate pH measurement across diverse industries before the advent of modern touchscreen and wireless sensors.

(H-20.5cm x W-16.5cm x D-28cm)