C65 POCKET CONDUCTIVITY METER

The C65 (often associated with Milwaukee Instruments as the EC65) is a high-performance, waterproof pocket meter designed to measure Electrical Conductivity (EC). It is specifically engineered for users in hydroponics, wastewater treatment, and laboratory environments who require precision in high-range salinity or nutrient concentration testing.

Key Performance Specifications

• Measuring Range: 0.00 to 20.00 mS/cm (milliSiemens per centimeter)

• Resolution: 0.01 mS/cm

• Accuracy: ±2% Full Scale

• Temperature Compensation: Automatic (ATC) from 5 to 50°C

• Calibration: Manual, 1 point (via trimmer)

• Waterproof Rating: IP65 (protected against water splashes and dust)

• Battery Life: Approx. 1500 hours (3 x 1.5V LR44/A76)

Core Features & Benefits

1. Replaceable Probe: The device features a modular design with a replaceable MA73076 probe. This significantly extends the life of the meter, as you don’t need to replace the entire unit if the sensor fails or becomes contaminated.

2. Automatic Temperature Compensation (ATC): Conductivity is highly sensitive to temperature changes. The C65 automatically adjusts readings to a standard reference temperature, ensuring accuracy regardless of environmental fluctuations.

3. Graphite Sensors: Unlike traditional stainless steel electrodes, graphite sensors provide a more stable reading and are highly resistant to the salt buildup and “polarization” common in nutrient solutions.

4. Rugged IP65 Housing: The casing is built to withstand wet laboratory or field conditions. It is designed to float if accidentally dropped into a tank.

Operational Guide: Calibration & Use

1. Calibration Procedure

• Step 1: Immerse the meter in the calibration solution (usually 12.88 mS/cm for high-range meters).

• Step 2: Stir gently and wait for the reading to stabilize.

• Step 3: Use the provided small screwdriver to adjust the calibration trimmer (located in the battery compartment or on the side) until the display matches the solution value.

• Step 4: Your meter is now calibrated. Periodic calibration is recommended every 1–2 weeks for high-usage environments.

2. Measurement

• Remove the protective cap and turn the meter on.

• Submerge the probe into the liquid sample.

• Stir gently to remove any air bubbles trapped around the graphite sensors.

• Wait for the display to stabilize and record the value.

Maintenance Tips for Longevity

• Rinse After Use: Always rinse the probe with distilled or tap water after measuring “dirty” samples (like hydroponic nutrients) to prevent mineral scaling on the graphite.

• Dry Storage: Unlike pH meters, conductivity probes should be stored dry. Simply rinse, shake off excess water, and replace the cap.

• Avoid Abrasives: Never touch or scrub the graphite sensors inside the probe. If they become dirty, soak them in a mild laboratory cleaning solution or alcohol for a few minutes.

• Battery Care: If the display becomes dim or erratic, replace all three 1.5V batteries simultaneously to maintain consistent voltage.

Common Applications

• Hydroponics: Measuring the “strength” of nutrient solutions to ensure plants receive optimal minerals.

• Water Treatment: Monitoring the salinity levels and total dissolved solids in industrial discharge.

• Boiler/Cooling Towers: Checking for mineral buildup in water systems to prevent pipe corrosion and scaling.

• Education: A reliable tool for teaching the principles of ionic concentration in chemistry labs.