Lab-grade pH for dairy, sauces, protein-containing liquids, and biotech samples — field-ready, IP57-rated.
The Apera PH850-DP (AI5535) is a portable pH meter kit purpose-built for liquid food and protein-containing samples — milk, yogurt, cream, sauces, TRIS buffers, enzyme solutions, and pharmaceutical/biotech fluids. It pairs the PH850 meter body with the Swiss-engineered LabSen 823 3-in-1 Glass pH/Temperature Electrode, a combination specifically designed to resist the junction clogs and reading drift that knock out standard electrodes in protein-rich matrices.
The Apera PH850-DP is a field-portable pH and temperature meter built on the PH850 platform and configured specifically for liquid food, dairy, and protein-containing sample matrices. The kit ships complete with the LabSen 823 glass combination electrode, pH 4.00 / 7.00 / 10.01 calibration buffer solutions, Protelyte soaking solution, carrying case, and all accessories needed to begin measuring out of the box.
The meter body delivers ±0.01 pH accuracy across a 0.00–14.00 pH range with selectable resolution of 0.01 or 0.1 pH. Temperature is measured simultaneously via the electrode's integrated NTC 30KΩ thermistor and compensated automatically (ATC), with a range of −5 to 100 °C (23–212 °F) and ±0.5 °C accuracy. The foldable stand on the back of the meter lets it double as a benchtop unit when you're working at a fixed station.
Standard pH electrodes fail quickly in dairy and protein-heavy liquids because proteins and sulfides foul the reference junction, causing drift and eventually an unreadable signal. The LabSen 823 is engineered around two specific countermeasures: a Silver Ion Trap reference system and Protelyte electrolyte. The silver ion trap absorbs exuded Ag⁺ ions and prevents them from reacting with proteins or sulfide-containing samples, protecting the reference junction from contamination. Protelyte is a tasteless, odorless, food-safe electrolyte that fully complies with EC Regulation 1935/2004 for contact with food products and does not react with protein.
The electrode's S-type hemispherical glass membrane is 10× stronger than conventional glass bulb membranes and delivers fully stabilized readings in 15–30 seconds. Apera's patented pH/temperature combination structure places the temperature element in an independent cavity directly beneath the glass membrane, increasing temperature response speed by 40% compared to a conventional isolated thermistor — which tightens ATC accuracy and shortens the overall stabilization window. The electrode is also compatible with TRIS buffers, making it a direct fit for biotech, pharmaceutical, and enzyme solution QC workflows.
The PH850 meter's self-diagnosis system actively monitors for out-of-range values and electrode invalidation, flagging issues before they produce bad data. Auto-calibration handles 1–3 calibration points and automatically recognizes USA and NIST series buffer solutions (1.68, 4.00, 7.00, 10.01, 12.45). After the second or third calibration point, the meter displays electrode slope — a direct indicator of electrode health that tells you whether the sensor needs reconditioning or replacement without any guesswork.
The IP57-rated body survives full immersion and wash-downs. A soft silicone grip sleeve provides secure handling in wet or gloved conditions and protects against general impact. Power comes from AA batteries (field-replaceable anywhere), auto power-off is configurable, and the large backlit LCD simultaneously displays pH and temperature with a stability icon that confirms when a reading has locked. BNC + RCA connectors are standard, and the meter is compatible with other Apera LabSen series electrodes for applications beyond liquid food.
For cannabis and hemp operators producing infused products, extracts, or any process where pH tracking through protein-containing or complex liquid matrices is required — tinctures, water-activity-sensitive edible production, nutrient solution QC in biotech-adjacent workflows — the AI5535 is the tool built for the job. Standard pen testers and general-purpose electrodes are not rated for protein-containing samples; junction clogging under those conditions produces inaccurate readings that accumulate calibration drift over time and ultimately fail entirely.
The AI5535 is equally at home in a quality lab, a processing room, or in the field for incoming material testing. The carrying case keeps the electrode, buffer solutions, and soaking solution organized for mobile use. The Protelyte maintenance system keeps the junction conditioned between uses, extending electrode service life in demanding sample matrices. Instrument warranty is three years; electrode warranty is six months per Apera's standard terms.
| SKU | AI5535 |
| Model | PH850-DP |
| pH Range | 0.00–14.00 pH |
| pH Accuracy | ±0.01 pH ±1 digit |
| pH Resolution | 0.01 or 0.1 pH (selectable) |
| Temperature Range | −5 to 100 °C (23–212 °F) |
| Temperature Accuracy | ±0.5 °C ±1 digit |
| Temp Compensation | Automatic (ATC) or Manual (MTC), 0–100 °C |
| Calibration | 1–3 point auto; recognizes USA & NIST series buffers (1.68, 4.00, 7.00, 10.01, 12.45) |
| Electrode | Swiss LabSen 823 Glass 3-in-1 pH/Temp., BNC + RCA connector |
| Electrode Temp Sensor | NTC 30KΩ |
| IP Rating | IP57 |
Standard combination electrodes use aqueous reference electrolytes that react with proteins and sulfides, causing junction clogging and reading drift in dairy and protein-containing liquids. The LabSen 823 uses Protelyte — a food-safe, protein-inert electrolyte — along with a Silver Ion Trap reference system that absorbs Ag⁺ ions before they can foul the junction. The result is stable, repeatable readings in sample matrices that would disable a general-purpose electrode within a short period of use.
Yes. The LabSen 823 electrode's Silver Ion Trap reference system specifically prevents the junction clogs caused by TRIS buffer solutions, sulfides, and proteins. This makes the AI5535 a direct fit for biotech QC, enzyme solution monitoring, pharmaceutical sample testing, and any workflow using TRIS-based buffers.
Both. The PH850 meter body has a foldable stand on the back that allows it to stand upright on a bench as a stationary instrument. For field or mobile use, the IP57 waterproof rating, silicone grip sleeve, and AA battery power make it suitable for processing rooms, wet environments, and portable QC work.
After completing a 2 or 3-point calibration, the PH850 displays the electrode slope value on the LCD. Slope is a direct measure of electrode health — a degrading electrode will show a slope outside the acceptable range, giving you an objective indicator to recondition or replace the LabSen 823 before measurement quality is compromised.
The PH850 auto-recognizes both USA series and NIST series standard buffer solutions: 1.68, 4.00, 7.00, 10.01, and 12.45 pH. The kit includes 4.00, 7.00, and 10.01 buffer solutions and Protelyte soaking solution for electrode maintenance.
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