APERA INSTRUMENTS / PH850-PW / AI5541

Low-ionic-strength water.
A more deliberate pH method.

PH850-PW pairs the straightforward PH850 Value-series meter with the refillable LabSen 803 pH/temperature electrode. Its cylindrical glass membrane and movable sleeve junction suit low-ionic-strength water, including RO, distilled and deionized samples.

Choose this kit when pure-water pH is the task and you will maintain a separate sample log. The instrument resolves 0.01 pH, but its stated ±0.01 pH ±1 digit accuracy is not a guarantee for every low-conductivity sample or collection method.

A junction designed for low ionic strength

LabSen 803 allows reference electrolyte to flow through a movable sleeve. Adjusting sleeve tightness changes flow; faster flow can support stabilization in low-ion samples. Recalibrate after an adjustment. The silver-ion-trap reference and low-resistance membrane support this application without making the electrode immune to contamination.

A readable field instrument

The backlit LCD shows pH and temperature together, with completed-calibration indicators and a stability symbol. The silicone sleeve and IP57-rated instrument enclosure support field handling, while the fold-out stand supports tabletop readings. Keep the electrical connectors clean and dry.

Calibration with visible feedback

Automatic recognition supports one to three calibration points using USA or NIST buffers. Use at least two points when connecting a new LabSen 803. Buffer recognition is not a substitute for fresh solutions or careful rinsing.

Know what this configuration supplies.

RO and deionized water checks

Use a defined collection and measurement routine for low-ionic-strength water. Exposure to air, carryover and electrolyte flow can influence the result, so compare like-for-like samples rather than treating one displayed value as an absolute purity test.

Distilled-water preparation

Follow pH trends in compatible prepared water while controlling handling conditions. A pH reading does not replace conductivity, resistivity or other tests needed to characterize water quality.

Low-ion environmental samples

Measure suitable collected storm or surface water within the electrode limits. Document sample temperature and collection conditions. This glass electrode is intended for liquid measurement, not pushing into sediment or rough field surfaces.

Limit air exposure.
Let the sample settle.

Connect the blue BNC plug for pH and the black RCA plug for temperature. Both functions are in the supplied electrode, with an integrated NTC 30 kΩ sensor. Start calibration at pH 7.00 in the USA buffer series, then add appropriate acidic or alkaline points. Use fresh buffer portions and rinse between solutions.

Remove the storage bottle, rinse the sensing end and open the blue refill plug before use. Check electrolyte level and sleeve condition. Use a clean vessel with enough sample to immerse the sensing membrane and junction consistently; select sample volume through your method rather than assuming a universal minimum.

Low-ion water readily changes on exposure to atmospheric carbon dioxide. Minimize unnecessary air contact and use a suitable closed sampling arrangement where the method requires it. Keep handling consistent, allow temperature and pH to stabilize, and observe the stability icon. Pure water is not a universal pH 7.00 check, and no fixed stabilization time applies to every sample.

Refill the reference.
Store the sensing end wet.

When reference solution drops to about half the electrode height, refill through the opening with the specified 3M KCl. This is separate from the blue inner sensing gel. Follow the electrode manual when adjusting or cleaning the sleeve; careless handling can damage its glass components.

After use, rinse off sample residue, close the refill plug and return the electrode to its storage bottle with 3M KCl soaking solution. Replace contaminated or insufficient solution. Distilled or deionized water is useful for rinsing, not for long-term electrode storage.

If response deteriorates, inspect the membrane, junction and connectors before replacing calibration buffers and recalibrating. Follow electrode-specific cleaning instructions and avoid scraping the sensing glass. The probe’s 0 to 80°C limit is narrower than the meter’s displayed temperature range.

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.

Read it. Record it. Keep your own sample log.

PH850 is a direct-reading Value-series instrument, not a data logger. There is no supported stored-reading recall, timed logging or computer export workflow for this model.

The stability icon helps you decide when to read. Optional automatic HOLD freezes a stable displayed result for transcription; it does not create a saved sample record. Record sample identity, pH, measured temperature, operator and your own date and time while the sample is still identifiable.

Keep calibration buffer details, electrode condition and any unusual drift alongside the result. A notebook or spreadsheet supplies the history; this kit does not promise software or automated reporting.