Name: Ohaus Starter ST20
Brand: Ohaus
Price: 104.62 USD

3.3/5#7 of 13 in pen testers ph meters
3.3

A pen tester from a lab-balance maker, for classrooms and labs buying Ohaus gear. The Apera PH60 is more accurate for less.

±0.05 pHAccuracy
3-pointCalibration
IP67Waterproof
YesReplaceable probe

Check price at Amazon$104.62

Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.

Pros

Three-point calibration and a replaceable electrode
IP67 housing

Cons

Only about 200 hours per set of batteries
No warranty published

How it scores

The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its type. How we rank explains each one.

Accuracy ±0.05 pH38
Calibration 3-point calibration85
Features replaceable probe, automatic temperature compensation, waterproof (IP67)80
Extra readings pH and temperature only0
Price $104.6276
Warranty warranty not published, scored as none0

Specifications

pH measurement
Model number	30073971
Accuracy	±0.05 pH
Resolution	0.01 pH
Range	0 to 14 pH
Calibration	3-point
Temperature compensation	Yes
Other readings
Conductivity (EC/TDS)	No
ORP	No
Salinity	No
Build
Replaceable probe	Yes
Waterproof rating	IP67
Battery life	200 hours
Weight	110 g

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±0.05 pH2-pointEC/TDS