Bluelab pH Pen - ± 0.1 pH Accurate - Durable Double Junction Probe
- Plus or minus 0.1 pH accuracy
- Double junction probe, glass
- Waterproof and floats
- Automatic temperature compensation
- 4.32 oz, 8 x 2.16 x 0.98 inches
- Made in New Zealand
Last refreshed Oct 3, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A waterproof, floating pH pen with a double junction probe and automatic temperature compensation. The listing says nothing about measurement range, calibration or batteries.
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ASIN: B005POOJHGCategory: pH Meters
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Overview
Bluelab builds this pen with a durable double junction probe and a waterproof body that floats. Automatic temperature compensation corrects readings as the liquid warms or cools.
Tight stated accuracy and a probe built for lasting use are the reasons to consider it, and the body floats. Range, calibration steps and power details are not given.
Who it's for
People who test water or solutions regularly and want a rugged, accurate pen. Buyers who need a certified calibration routine or replaceable probe information should confirm those first.
Pros and cons
- Tight accuracy for a pen
- Double junction probe
- Waterproof body that floats
- Automatic temperature compensation
- Range not listed
- Glass probe needs gentle handling
- Calibration steps not described
Performance notes
A double junction probe resists contamination from the sample, which helps readings stay stable between calibrations. Automatic temperature compensation corrects for the sample temperature so the pH value is consistent. Rinsing after use protects the glass sensing element.
Where it stands among ph meters
- #2 most-searched brand and model of the 8 ph meters lines we track (by search demand, not sales).
From the specs of the 15 ph meters we list; not a test result.
Specifications
| Brand | Bluelab |
|---|---|
| Dimensions & fit | |
| Dimensions | 8 x 2.16 x 0.98 inches |
| Weight | 4.32 ounces |
| Capacity & performance | |
| Temperature compensation | Automatic |
| Construction & materials | |
| Material Type | Glass |
| Other details | |
| Accuracy | plus or minus 0.1 pH |
| Probe | Double junction |
| Water resistance | Waterproof, floats |
| Made in | New Zealand |
Closest rivals on specs
APERA INSTRUMENTS AI209 Value Series PH20 Waterproof pH Tester Kit- Item Weight 0.27 vs 0.24 pounds (+13%)
VIVOSUN Digital pH Meter 0.01 Accuracy Pen Tester for Water Hydroponics- Item Weight 0.27 vs 0.24 pounds (+13%)
Frequently asked questions
How do I take care of the Bluelab pH Pen?
The listing gives no storage or probe care steps. It describes a waterproof body that floats and a durable double junction probe.
Does the Bluelab pH Pen compensate for temperature?
Yes. The item highlights list automatic temperature compensation.
Where is the Bluelab pH Pen made?
The item highlights say it is made in New Zealand.