HM Digital Pro Series Pen Style TDS/EC/Temp Meter - 7.28 x 1.34 x 1.34-in - IP-67 Waterproof

Check Nutrient Strength and Temperature in One Reading - Waterproof Pen Format

Guessing solution strength leads to inconsistent feeding, and carrying separate tools slows every reservoir check. This meter measures electrical conductivity (EC), total dissolved solids (TDS) and temperature with a single handheld pen. Its housing carries an IP-67 waterproof rating, is submersible and floats, so a drop into a reservoir is not a problem.

Sold as a single unit, this pen suits home gardeners who want a dependable tool for routine checks, and it works equally well as a spare or per-room meter for commercial growers running several reservoirs. It measures 7.28 in long and 1.34 in wide, so it fits in a pocket or tool pouch.

Key Features & Benefits

• EC range of 0 – 9990 µS (0 – 9.99 mS) — covers a wide span of solution strengths.
• Temperature range of 0-55 °C (32-130°F) — shows solution temperature alongside the conductivity reading.
• Detachable platinum electrodes with replaceable sensor (model SP-C1) — lets you renew the probe rather than the whole meter.
• Accuracy of +/- 2% — gives consistent readings for tracking feed changes.
• Factory calibrated with 1413 µS solution — ready to use out of the box.

Who Should Use HM Digital Pro Series Pen Style TDS/EC/Temp Meter

Growers who mix nutrient solutions, monitor reservoirs or test water before feeding will find this meter useful. It suits hobbyists, indoor growers and commercial operations that want a compact, waterproof meter.

About HM Digital Pro Series Pen Style TDS/EC/Temp Meter

HM Digital makes this pen style meter under product code HM-COM-100. It runs on 2 AAA batteries, which are included along with a translucent cap and a lanyard. It measures 7.28 x 1.34 x 1.34 in.

Frequently Asked Questions

Q: What does this meter measure?
A: It measures electrical conductivity (EC), total dissolved solids (TDS) and temperature. EC readings range from 0 to 9990 µS, or 0 to 9.99 mS. Temperature readings range from 0 to 55 °C.

Q: Can it get wet?
A: Yes. The housing has an IP-67 waterproof rating, is submersible and floats. You can place it in a solution to take a reading.

Q: Is it calibrated when it arrives?
A: Yes, it is factory calibrated with a 1413 µS solution. Check it against a known reference solution if you want to confirm it before use.

Q: What happens when the probe wears out?
A: The electrodes are detachable and the sensor is replaceable, model SP-C1. You can swap the sensor instead of replacing the whole meter.

Q: What is the difference between EC and TDS?
A: EC measures how well a solution conducts electricity, which reflects the dissolved salts in it. TDS is an estimate of the total dissolved solids, calculated from that conductivity reading.

Q: What is included?
A: The meter comes with a translucent cap, 2 AAA batteries and a lanyard.