APERA INSTRUMENTS / PC820 / AI533

Finer pH resolution.
Separate sensors, deliberate measurements.

PC820 pairs a precision benchtop meter with the refillable LabSen 211 pH electrode, a separate MP500 temperature probe and a 2401T-F glass conductivity/temperature electrode. The AI533 kit is built for sequential pH and conductivity measurements, not simultaneous multi-parameter acquisition.

Choose this configuration when 0.001 pH resolution and ±0.002 pH ±1 digit meter accuracy support your method. The long-life pH reference and glass conductivity cell bring distinct care requirements. Assess the supplied electrodes against the sample: the meter’s extended electronic ranges do not extend either sensor’s published limits.

A serviceable pH reference system

LabSen 211 has a hemispherical S-type glass membrane, blue internal gel, ceramic junction and long-life reference. The outer reference electrolyte is refillable 3M KCl; it is distinct from the blue gel. The electrode is intended for general aqueous samples and is identified as TRIS-compatible. It has a pH-only BNC connection, not an integral temperature sensor.

Conductivity sensing within a defined range

The supplied 2401T-F uses a K=1 platinum-black cell, glass body and integrated 30 kΩ thermistor with BNC/RCA connections. Its published measurement range reaches 200 mS/cm. PC820 electronics extend to 2000 mS/cm, but that upper meter limit requires a suitable different cell and method; it is not the supplied kit’s ready-to-use probe range. The supplied K=1 probe is rated to 200 mS/cm, but the meter manual recommends K=10 for measurements above 100 mS/cm. Choose the cell and calibration for the method; an optional high-range electrode is not included.

More calibration points, not automatic certainty

USA/NIST recognition supports one to three pH calibration points in 3P mode or one to five in 5P mode. Customized pH calibration is a separate one- or two-point procedure and requires calibration and measurement at the same temperature. Conductivity standard calibration supports one to four points; customized conductivity calibration is a separate one-point procedure.

Know what this configuration supplies.

Precision aqueous laboratory work

Use for compatible buffer preparations and water-based samples where calibration control and finer pH resolution are useful. Confirm temperature, matrix compatibility and an independent check standard before interpreting small differences.

Paired pH and conductivity records

For sample batches requiring both acidity and ionic-conduction information, measure sequentially and retain a shared sample identifier outside the meter. This configuration avoids two meters but does not acquire both values concurrently.

Conductivity-derived concentration checks

TDS, salinity and resistivity modes use the conductivity electrode. TDS uses a selectable 0.40 to 1.00 conversion factor, default 0.71. These results support a defined comparison method; they do not identify dissolved substances or certify sample safety.

Match the temperature input.
Keep the two calibration paths separate.

Connect LabSen 211 to the pH/mV BNC socket and MP500 to the shared TEMP RCA socket for pH work. Connect 2401T-F to COND and use its RCA temperature lead for conductivity. LabSen 211 and MP500 must sense the same sample. The shared temperature input is not an extra independent channel, and the exact manual says pH and conductivity cannot be measured simultaneously.

For a newly connected LabSen 211, perform at least two-point pH calibration. Open its blue refill plug during measurement and maintain electrolyte level. For conductivity, select K=1 and calibrate from low to high concentration with clean portions of suitable standards. The meter supports four EC points, but only three conductivity standards are supplied. Recognized 111.8 mS/cm is an additional standard, not a kit bottle.

pH compensation corrects the electrode’s temperature response and does not normalize sample chemistry to 25°C. Conductivity compensation instead uses an adjustable reference temperature of 15 to 30°C, default 25°C, and coefficient of 0.00 to 9.99%/°C, default 2.00%/°C. Zero coefficient selects uncompensated conductivity. Confirm the coefficient for the solution and allow both temperature and measurement to stabilize.

Refill the pH reference.
Do not share storage solutions.

LabSen 211 requires 3M KCl, AI1107, for both reference refill and external wet storage. Refill when the electrolyte falls to about half the electrode height. Rinse before storage, close the refill plug and tighten the storage bottle. Distilled or deionized water is suitable for rinsing, not long-term storage of this pH electrode.

The 2401T-F conductivity electrode instead belongs in its cap with clean distilled or deionized water. Replace contaminated cap water and rinse thoroughly between samples. Gently move the cell in the sample to release air; never rub the sensor. Protect the glass bodies from impacts and keep BNC/RCA connectors dry.

LabSen 211 is specified for 0 to 14 pH and -5 to 100°C, narrower than the meter’s -2.000 to 19.999 pH range. Its instructions warn against strong acids, strong alkalis and dehydrating media. For difficult residue, its manual specifies electrode cleaner followed by KCl reconditioning and recalibration. Neither a sturdy reference design nor IP54 instrument protection makes the electrodes unbreakable. The page lists -10 to 110°C temperature measurement, but the meter manual lists 0 to 100°C; confirm instrument revision before relying on the wider interval.

Read the display. Check the measurement mode.

Use the physical controls for measurement, calibration and the documented record functions. Check units, temperature, calibration indicators and the selected parameter before assigning a result to a sample. Screen values in photographs are illustrative, not sample results. The model-specific record and output workflow is explained below.

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.

1000 mode-specific records.
Not 1000 combined sample bundles.

The exact 820-series manual allocates 1000 stored records to PC820 and 500 to PH820/EC820. The current PC820 page contains both 500 and 1000 claims; its specification table and model-specific manual support 1000. Stored entries contain record number, date, time, measurement, unit and temperature. They represent the active mode, not a simultaneous pH-plus-conductivity row.

Manual saving, timed storage and USB download support repeatable recordkeeping. Legacy PC-Link categorizes readings by pH, mV and conductivity and exports to an Excel file. In connected real-time logging, data are sent to the computer rather than also retained in meter memory. Keep sample identity, standards and acceptance checks alongside exported results.

The legacy manual describes Windows PC-Link, not Mac software. Current kit pages additionally link a newer Web PC-Link service. These are distinct workflows: confirm the meter revision, USB driver and browser support before depending on the newer route. The web application's own compatibility message names Chrome, Edge and Opera, while the kit page also names Firefox. Universal browser or Mac operation is not established here. No software installation or live instrument connection was tested. These functions do not supply validated LIMS integration or establish GLP compliance.