APERA INSTRUMENTS / PH850-DP / AI5535

Protein-containing liquids.
A reference built for the task.

PH850-DP combines the PH850 Value-series portable meter with the refillable LabSen 823 pH/temperature electrode. Its silver-ion-trap reference, three ceramic junctions and Protelyte electrolyte suit dairy products, compatible liquid foods and selected protein-containing laboratory samples.

Choose DP when the reference chemistry matters as much as the displayed pH. The electrode is designed to reduce protein-related junction problems, not eliminate cleaning or certify a formulation. Establish suitability for your sample composition and work within the complete measurement system’s temperature limits.

Reference chemistry for protein-containing samples

LabSen 823 uses Protelyte around a silver-ion-trap reference and three ceramic junctions. This combination targets reference contamination and clogging in suitable protein-containing liquids. It remains a refillable, serviceable electrode: residue must be removed and electrolyte maintained. The blue inner gel is distinct from the outer reference solution you replenish.

Temperature measured at the probe

LabSen 823 incorporates an NTC 30 kΩ temperature sensor. The meter displays temperature alongside pH and supports automatic compensation. This corrects the electrode response, not the sample’s chemistry. A warm sample can genuinely differ from the same sample after cooling, so report temperature with pH.

Portable controls without a software workflow

The LCD provides a stability symbol and completed-calibration indicators. A protective sleeve, fold-out stand and IP57 instrument enclosure support portable use. Automatic buffer recognition and selectable stability criteria help standardize operation, while the operator remains responsible for calibration quality, clean connections and a separate record of each result.

Know what this configuration supplies.

Dairy and compatible liquid foods

Use a defined sampling method for milk, cream, yogurt and suitable sauces or other liquid foods. Ensure the sensing glass and junctions are properly immersed. Thick or heterogeneous samples may need a validated preparation procedure; the round glass tip is not intended to puncture solid food.

Protein-containing laboratory liquids

Consider the 823 configuration for compatible biological fluids, enzyme solutions and protein-containing preparations. Review the entire matrix, including cleaners and solvents, before use. Suitability for these applications does not make the kit a sterile instrument, a diagnostic test or a release-testing compliance system.

TRIS-buffered aqueous preparations

The manufacturer identifies the 823 reference system and Protelyte for compatible TRIS applications. That is not blanket compatibility with every concentration, additive or temperature. Use appropriate calibration and method controls for the actual preparation, and investigate persistent drift rather than treating it as a finished result.

Prepare a representative sample.
Read only after stabilization.

Connect the blue BNC plug for pH and the black RCA plug for temperature. Remove the storage bottle, rinse the sensing end with distilled or deionized water, and open the blue refill plug so electrolyte can flow. Inspect the reference level before starting. A newly connected LabSen 823 requires at least a two-point calibration before measurement.

The PH850 recognizes USA or NIST buffers and supports one to three calibration points. In USA mode, begin with pH 7.00 and add suitable points for the expected sample range. Use fresh portions of buffer and rinse between solutions. Do not pour used buffer back into its bottle; a displayed calibration indicator cannot establish that a contaminated standard was valid.

For dairy and protein samples, maintain a consistent collection, mixing and immersion procedure without striking the vessel with the glass tip. Use sufficient sample to cover the membrane and all junctions. Let temperature and pH stabilize and watch the stability symbol. No fixed sample volume or universal reading time is promised; characterize the response in your own matrix.

Protelyte inside.
Protelyte for storage.

When the reference solution falls to about half the electrode height, refill through the opening with Protelyte AI1190. The exact LabSen 823 instructions specify Protelyte for both reference refill and external soaking. Do not substitute generic KCl merely because it is used with other pH electrodes.

Rinse sample residue from the electrode before and after use. Return it to the storage bottle containing clean Protelyte, tighten the cap and close the refill plug. Replace contaminated or insufficient solution. Pure water is appropriate for rinsing, not long-term storage. Keep the BNC and RCA connectors clean and dry even though the instrument itself has an IP57 rating.

For tough contamination, the exact electrode manual specifies Apera AI1166 cleaner for 30 minutes, gentle removal with a soft brush, then at least one hour in Protelyte. Rinse and recalibrate before measuring again. Do not scrape the glass membrane. The electrode manual advises avoiding strong acids, strong alkalis and dehydrating media such as absolute ethanol. Do not assume compatibility from the stated pH range alone.

A stable reading is the start of the record.

Use the physical controls for on-meter measurement and calibration. HOLD temporarily locks a reading on screen; write the result and its sample context in your external worksheet or record system. Screen values in photographs are illustrative, not sample results.

Use calibration solutions and settings appropriate to the parameter and fitted electrode. Temperature compensation does not make different sample temperatures, preparation methods or chemistry equivalent. Follow the model-specific meter and electrode instructions before extending the method to a new sample.

A readable result, not a stored sample record.

PH850 is a direct-reading Value-series instrument. Its current specification lists reading storage, storage content and output as N/A. Choose a separate recordkeeping method before starting a sample series; this meter does not supply stored-reading recall or a computer export workflow.

Optional automatic HOLD freezes a stable reading on the display. It helps with transcription but does not save the sample or create a timestamped entry. Record sample identity, pH, measured temperature, operator and your own date and time while the result is still associated with the correct vessel.

Retain buffer details, calibration checks and electrode-care observations alongside the sample result. For work governed by a quality procedure, use the organization’s approved worksheet and acceptance rules. The kit does not itself establish traceability, food safety, pharmaceutical release status or regulatory compliance.