Apera Instruments AI104G GroStar Series GS4 pH/EC/500ppm/700ppm Combo 5-in-1 Pen Tester Kit with Replaceable Double-Junction pH/EC Probe for Hydroponics Water Quality Testing, Gen II

pH/EC/500ppm/700ppm/Temp. all in 1

Simply measures pH, EC, 700ppm, 500ppm, and temperature simultaneously with a single tap of the Mode button.

Premium pH/EC Combo Sensor Tech

• The premium combo probe is featured with a double-junction pH sensor and a titanium conductivity sensor, ensuring accurate pH/EC/ppm measurements in the long run.
• The probe is replaceable just so you only need to replace the probe when it reaches its end of life instead of buying a whole new tester.

Grower-friendly Auto. Calibration

The grower-friendly auto. calibration workflow allows you to finish 2-point calibration within a minute. M or L icons will appear after calibration to let you know the meter is successfully calibrated, and will disappear in 30 days to remind you to re-calibrate.

Electrode Condition Display

After finsihing the 2nd point calibration, the slope data of the pH electrode will show up, indicating the health condition of your pH electrode. The closer the slope is to 100%, the better the electrode's conditon is. In general, we would consider 97% to 100% as great condition, 93% to 96% as good condition. If below 90%, it means your pH electrode is close to its end of life, and we recommend replacing it to ensure the optimal measurement accuracy.