Oakton pHTestr 30
#3 in Pen testersFull review
A lab-brand pocket tester with a replaceable module, for labs and schools that already stock Oakton parts.
Amazon $136.22$136.22
The Oakton pHTestr 30 is the better ph meter overall, rated 3.7 to 3.6. The Extech ExStik II PH100 wins on features. The Extech ExStik II PH100 costs $6.72 less ($129.50 vs $136.22).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Extech ExStik II PH100
#5 in Pen testersFull review
A pen with a flat electrode for checking cheese, meat, paper or wet surfaces as well as liquids.
Amazon $129.50$129.50
Which should you buy?
- Choose the Extech ExStik II PH100 for features (replaceable probe, automatic temperature compensation, waterproof, stores readings vs replaceable probe, automatic temperature compensation, waterproof (IP67)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every pen testers ph meter; a clear win is highlighted. How we rank explains each one.
| Factor weight | Oakton pHTestr 30 | Extech ExStik II PH100 |
|---|---|---|
| Overall rating | 3.7/5 | 3.6/5 |
| Accuracy 30% | 81 ±0.01 pH | 81 ±0.01 pH |
| Calibration 15% | 85 3-point calibration | 50 calibration points not published (neutral score used) |
| Features 20% | 80 replaceable probe, automatic temperature compensation, waterproof (IP67) | 90 replaceable probe, automatic temperature compensation, waterproof, stores readings |
| Extra readings 10% | 0 pH and temperature only | 0 pH and temperature only |
| Price 15% | 64 $136.22 | 67 $129.50 |
| Warranty 10% | 0 warranty not published, scored as none | 0 warranty not published, scored as none |
Specifications
| Oakton pHTestr 30 | Extech ExStik II PH100 | |
|---|---|---|
| pH measurement | ||
| Accuracy | ±0.01 pH | ±0.01 pH |
| Resolution | 0.01 pH | 0.01 pH |
| Range | -1 to 15 pH | 0 to 14 pH |
| Calibration | 3-point | - |
| Temperature compensation | Yes | Yes |
| Other readings | ||
| Conductivity (EC/TDS) | No | No |
| ORP | No | No |
| Salinity | No | No |
| Build | ||
| Replaceable probe | Yes | Yes |
| Waterproof rating | IP67 | Waterproof |
| Stored readings | - | 15 readings |
| Battery life | 500 hours | - |
| Weight | 90 g | - |