ADWA AD31 TDS and Conductivity Tester

Measure EC, TDS and Temperature with One Pocket Tester

The ADWA AD31 TDS and Conductivity Tester combines electrical conductivity (EC), Total Dissolved Solids (TDS) and temperature measurement in a compact waterproof instrument designed for routine water quality testing.

With an EC range of 0 to 3999 µS/cm and a TDS range of 0 to 2000 ppm, the AD31 is Adwa’s low-range EC/TDS pocket tester, making it particularly suitable for hydroponics, aquaculture, water treatment, laboratory and general water quality applications.

Measure Conductivity up to 3999 µS/cm

The AD31 measures electrical conductivity from 0 to 3999 µS/cm with 1 µS/cm resolution. Conductivity measurement provides a practical way to monitor the concentration of dissolved ionic substances in water and nutrient solutions.

Check TDS up to 2000 ppm

Total Dissolved Solids can be displayed directly from 0 to 2000 ppm with 1 ppm resolution, allowing users who work primarily with TDS values to read results without manually converting conductivity measurements.

Adjustable EC-to-TDS Conversion Factor

The EC/TDS conversion factor can be adjusted from 0.45 to 1.00, allowing the relationship between conductivity and displayed TDS to be configured for different testing requirements.

Automatic Temperature Compensation

Conductivity and TDS readings are automatically temperature compensated between 0°C and 60°C. The temperature compensation coefficient (β) can also be adjusted from 0.0 to 2.4%/°C.

Measure Water Temperature at the Same Time

The temperature sensor incorporated into the probe measures from 0.0°C to 60.0°C. Temperature can be displayed in either °C or °F while also providing the measurement required for automatic EC and TDS temperature compensation.

Replaceable AD32P Probe

The supplied AD32P EC/TDS/temperature probe is user-replaceable. When the probe eventually requires replacement, a new sensor can be installed without replacing the complete tester.

Automatic One-Point Calibration

The AD31 provides automatic one-point calibration. Depending on the selected measurement mode, calibration can be performed using 1413 µS/cm, 1382 ppm or 1500 ppm standards.

Waterproof Design for Routine Water Testing

The AD31 housing is sealed against humidity and designed as a waterproof pocket tester, making it suitable for routine measurements around water, nutrient solutions and other aqueous samples.

Stability Indicator for Easier Measurements

A stability indicator on the LCD helps identify when the measured value has stabilised, while the HOLD function allows the current measurement to be retained on the display for convenient recording.

Key Features

• Measures conductivity (EC), TDS and temperature
• Waterproof pocket tester design
• 0 to 3999 µS/cm EC measurement range
• 0 to 2000 ppm TDS measurement range
• 0.0°C to 60.0°C temperature measurement range
• Automatic Temperature Compensation (ATC)
• Adjustable EC/TDS conversion factor from 0.45 to 1.00
• Adjustable temperature compensation coefficient
• Automatic 1-point calibration
• User-replaceable AD32P probe
• Dual-line LCD
• Stability indicator
• HOLD function
• Battery level indication
• Low battery warning
• Automatic power-off after 8 minutes

Technical Specifications

Model	ADWA AD31
Measurement	Conductivity (EC), TDS and Temperature
EC Range	0 to 3999 µS/cm
EC Resolution	1 µS/cm
TDS Range	0 to 2000 ppm
TDS Resolution	1 ppm
EC/TDS Accuracy at 25°C	±2% F.S.
Temperature Range	0.0°C to 60.0°C (32.0°F to 140.0°F)
Temperature Resolution	0.1°C / 0.1°F
Temperature Accuracy at 25°C	±0.5°C / ±1°F
Calibration	Automatic, 1 point
Calibration Standards	1413 µS/cm, 1382 ppm or 1500 ppm
TDS Conversion Factor	User adjustable from 0.45 to 1.00
Temperature Compensation	Automatic from 0°C to 60°C
Temperature Coefficient (β)	Adjustable from 0.0 to 2.4%/°C
Probe	AD32P replaceable EC/TDS/temperature probe
Display	Dual-line LCD
Battery	4 × 1.5V button batteries
Battery Life	Approx. 100 hours
Auto-Off	After 8 minutes of inactivity
Operating Environment	-5°C to 50°C; RH 100%
Dimensions	175.5 × 39 × 23 mm
Weight	100 g

Typical Applications

• Hydroponics and nutrient solutions
• Aquaculture
• Water quality testing
• Water treatment
• Agriculture and irrigation water
• Laboratory water testing
• Environmental monitoring
• General aqueous sample testing

What’s Included?

• ADWA AD31 Waterproof EC/TDS/Temperature Tester
• AD32P Replaceable EC/TDS/Temperature Probe
• 1413 µS/cm Calibration Solution – 20 ml Sachet
• Protective Cap
• Clip Holder
• Wrist Strap
• 4 × 1.5V Button Batteries
• Instruction Manual

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