pH Probe by Bluelab — 2m BNC Replacement Probe for Bluelab Meters, Monitors & Controllers
BL-MTR-PROBE-PH-2M
Pairs well with
The Bluelab pH Probe is the standard 2-metre BNC replacement probe for Bluelab meters, monitors and controllers. When your Guardian or pH Controller starts drifting and cleaning won't bring it back, this is the part you swap — a double-junction, gel-filled probe in a polycarbonate body, with the probe holder suction cup and a KCl-filled storage cap in the box. Connect it, calibrate it, and your readings are trustworthy again without replacing the whole unit.
Specifications
0.0–14.0 pH
±0.1 pH
Double junction, Ag/AgCl, saturated KCl gel (non-refillable)
Standard BNC, waterproof cable joint
2 metres / 6.5 feet
Polycarbonate, waterproof probe
0–60°C / 32–144°F
Probe holder with suction cup, KCl-filled storage cap
6-month limited warranty
Bluelab, New Zealand
- The probe tip must stay wet at all times. When it's not in the reservoir, keep the storage cap on with enough Bluelab KCl storage solution to cover the tip. Never use RO, distilled or deionised water — pure water changes the reference chemistry and kills the probe.
- If the tip has dried out or hasn't been stored in KCl, clean it, then stand it in a container of KCl solution submerging the tip for at least 24 hours, and calibrate afterwards.
- Handle it like the glass instrument it is: always loosen the storage cap before pulling it off, don't bend or knock the probe, don't kink the lead, and never let the BNC connector get wet.
How to Install and Calibrate
Pairs Well With
The devices this probe keeps honest — browse the full Bluelab range.
Calibration & KCl SolutionspH 7.0 and 4.0 standards for monthly calibration, KCl storage solution to keep the tip alive.
Meters & PensHandheld pH and EC testing for spot checks alongside your monitored reservoir.
Water ControlpH Up and Down, dosing gear and reservoir hardware to act on the readings.
Frequently Asked Questions
Does this probe fit the Bluelab Guardian and pH Controller?
Yes. It's compatible with Bluelab handheld meters, monitors and controllers that use a standard BNC probe connection, including the Guardian Monitor, pH Controller and Combo Meter.
Does it fit the Bluelab pH Pen or pH PenPlus?
No. The pens don't take a BNC probe — the pH Pen's probe is fixed, and the pH PenPlus uses its own screw-in pH ProbePlus, which we stock separately.
Does the probe need calibrating before use?
Yes. Calibrate before first use (no cleaning required for that initial calibration) and then monthly — always 2-point, pH 7.0 first, then 4.0 or 10.0. Clean the probe before every calibration after the first.
What warranty does it carry?
The Bluelab pH Probe carries a 6-month limited warranty with proof of purchase. pH probes are consumable glass instruments — they age with normal use, and lifespan depends heavily on storage and care.
Why is my probe drifting or stuck on one reading?
Drift usually means a contaminated or dried-out tip — clean it, hydrate it in KCl storage solution for 24 hours, and recalibrate. A probe that reads the same in every buffer has broken glassware and needs replacing. If it reads pH 7 for everything, check the BNC fitting and cable for damage or moisture first.
Can the BNC connector get wet?
No. The probe and cable joint are waterproof, but the BNC connector at the meter end must stay dry — a wet fitting causes false readings and isn't covered under warranty.
Bring Your Bluelab Back to Accurate
Genuine Bluelab replacement probe, holder and KCl cap included. Free shipping over $499*.