Lab-grade pH measurement in high-temperature and caustic solutions, rated to 130°C.
The Apera PH850-HT (SKU: AI5564) is a field-ready portable pH meter built specifically for high-temperature liquids and chemically aggressive solutions. Paired with the Swiss LabSen 863 pH/Temp. electrode—featuring a PHY glass membrane and PTFE ring junction—it delivers ±0.01 pH accuracy across solution temperatures up to 130°C, in an IP57-rated silicone-protected body powered by standard AA batteries.
The Apera PH850-HT is a portable pH, ORP, and temperature meter from Apera Instruments' Value Series (850 line), purpose-built for sample environments that destroy standard electrodes: high-temperature process liquids, electroplating solutions, strong alkaline media, and other caustic or complex chemistries. Where conventional pH electrodes fail quickly from chemical corrosion or thermal stress, the PH850-HT is matched with a LabSen 863 electrode engineered specifically for those conditions.
The meter's core platform is the proven PH850 body—a field-grade portable unit with a large LCD displaying simultaneous pH and temperature readings, a foldable stand that converts it to benchtop use, and a standard BNC connector that accepts the full Apera LabSen electrode lineup. The PH850-HT variant ships with the LabSen 863 already installed, with calibration buffers included, ready to run.
The LabSen 863 is the highest-durability electrode in Apera's Swiss-technology LabSen series. Its PHY glass membrane is the most chemically resistant in the lineup, rated to withstand continuous exposure to caustic solutions and temperatures up to 130°C without degraded accuracy or shortened service life. This is the electrode to reach for when measuring electroplating baths, strong alkaline process streams, or any high-temp sample that would foul or crack a standard glass bulb.
Junction clogging—the most common failure mode when measuring complex or protein-heavy solutions—is addressed by a PTFE ring junction that resists fouling from aggressive chemicals, combined with a silver-ion-trap reference system that absorbs exuded Ag+ to prevent sulfide or protein-caused blockages. The non-flowing blue gel inner solution eliminates air bubble formation that causes heat convection and reading drift, and means the electrode can be used in any orientation without affecting accuracy. The built-in thermistor sensor enables real-time automatic temperature compensation (ATC).
Calibration on the PH850-HT follows a 1–3 point auto-recognition protocol, scanning for standard buffers at pH 1.68, 4.00, 7.00, 10.01, and 12.45. After the second and third calibration points, the meter displays the electrode slope—a direct indicator of electrode condition that lets operators know when the probe is performing within spec versus when it needs service or replacement. The self-diagnosis engine flags out-of-range values and electrode invalidation in real time, taking the guesswork out of troubleshooting field readings.
A stability icon (smiley face) appears on the LCD when the reading has settled—a practical feature in cultivation environments where airflow and solution motion can cause transient drift. Auto power-off extends battery life during long measurement sessions. ORP measurement is available in mV mode when an ORP probe (model 301Pt-C, sold separately) is connected via the BNC port, making the meter multifunctional without adding a separate instrument.
In licensed cannabis and hemp facilities, the PH850-HT's primary value is in environments where standard pH meters lose accuracy or fail prematurely. Nutrient reservoirs running elevated temperatures (recirculating deep water culture systems, heated coco lines in cold rooms), pH Up/Down stock solutions, alkaline sanitizing or sterilizing agents used between cycles, and foliar spray concentrates all represent sample conditions that stress a general-purpose electrode.
The meter is equally capable as a standard nutrient solution checker—a commercial cultivation team checking fertigation lines, reservoir pH, or runoff across dozens of sites needs a meter that holds calibration, handles variable sample chemistry, and survives drops and spray. The IP57 rating, rubber-over-silicone grip, and AA battery power (no proprietary charging cable) make the PH850-HT a practical daily driver. The BNC connector preserves future flexibility: if a grow operation introduces a sample type requiring a different specialized LabSen electrode, the meter body stays and only the probe swaps.
| SKU | AI5564 |
| Model | PH850-HT |
| Included Electrode | LabSen 863 pH/Temp. (Swiss sensor technology) |
| pH Range | 0.00–14.00 pH |
| pH Resolution | 0.1 / 0.01 pH (selectable) |
| pH Accuracy | ±0.01 pH ±1 digit |
| ORP (mV) Range | ±1,000 mV |
| ORP Resolution / Accuracy | 1 mV / ±0.2% F.S. ±1 digit |
| Solution Temperature Range | 0–130°C (electrode-rated) |
| Temperature Compensation | Automatic (ATC), built-in thermistor |
| Calibration | 1–3 point auto, recognizes 1.68 / 4.00 / 7.00 / 10.01 / 12.45 pH buffers |
| Waterproof Rating | IP57 |
The LabSen 863 uses a PHY glass membrane—the most chemically robust membrane in Apera's LabSen lineup—rated to withstand continuous exposure to caustic and high-temperature solutions up to 130°C. A standard general-purpose electrode uses a standard glass bulb membrane that degrades rapidly under those conditions, leading to drifting readings and early probe failure. The 863 also uses a PTFE ring junction to resist fouling from complex chemicals and a silver-ion-trap reference system to prevent junction clogs from sulfides or proteins.
Yes. When switched to mV mode and connected to a compatible ORP electrode (Apera model 301Pt-C, SKU AI1303, sold separately via BNC connector), the PH850-HT measures ORP in the ±1,000 mV range at 1 mV resolution. The standard LabSen 863 electrode included with the PH850-HT does not measure ORP—you need the separate ORP probe for that function.
The PH850-HT displays electrode slope after completing a 2- or 3-point calibration. Slope is a direct indicator of electrode health—a deteriorating electrode will show a slope value outside the normal range before it begins giving visibly inaccurate readings. The self-diagnosis function will also flag out-of-range values and electrode invalidation on screen, so operators get an active warning rather than quietly wrong data.
Yes. The PH850 meter body uses a standard BNC connector that accepts the full Apera LabSen series. If your facility has multiple sample types—standard nutrient solutions, high-temp process streams, pure water, meat or dairy for processing operations—you can purchase the appropriate LabSen electrode for each application and use the same PH850-HT meter body. Note: LabSen electrodes with built-in thermistors may not be compatible with third-party meter brands due to thermistor spec differences.
IP57 means the meter is dust-tight (6 = full dust protection, though rated at 5 here) and protected against immersion in water up to 1 meter for up to 30 minutes. In practical cultivation terms, it survives direct spray from irrigation lines, accidental submersion in a reservoir, and daily exposure to humid greenhouse or grow-room environments. The silicone case provides additional impact protection if the meter is dropped on a concrete floor.
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