The Apera GroStar GS3 (AI103G) is a Generation II, lab-grade conductivity meter designed for commercial cultivation and nutrient-solution monitoring. It measures four parameters: electrical conductivity (EC), total dissolved solids (TDS) on the 500 ppm scale, TDS on the 700 ppm scale, and temperature. Its replaceable titanium-alloy conductivity probe is designed to resist corrosion from concentrated nutrient solutions, while automatic temperature compensation helps maintain reliable EC readings as solution temperatures change. The IP67-rated, waterproof and dust-protected design makes it suitable for routine testing of reservoirs, fertigation lines, and runoff. Its TruRead mode records stabilized readings at seven-second intervals and displays the average, minimum, and maximum, helping growers compare solution consistency across multiple sampling points.
• Product Type: EC/PPM/temperature pen tester
• Brand: Apera Instruments
• Model: GroStar GS3 Gen II
• SKU: AI103G
• Measurement Parameters: EC, 500 ppm, 700 ppm, and temperature
• EC Measurement Range: 0–10.0 mS/cm
• EC Accuracy: ±0.1 mS/cm
• 500 ppm Range: 0–5,000 ppm (NaCl conversion scale)
• 700 ppm Range: 0–7,000 ppm (KCl conversion scale)
• Temperature Range: 0–50°C (32–122°F)
• Temperature Accuracy: ±1°C / ±1°F
• Resolution: 0.1 mS/cm for EC; 10 ppm for both ppm scales; 0.1°C / 0.1°F for temperature
• Sensor Type: Replaceable titanium-alloy conductivity probe
• Temperature Compensation: Automatic (ATC) using a built-in thermistor
• Calibration: Automatic one-point EC calibration using a 2.77 mS/cm standard solution
• Calibration Reminder: Automatic reminder after 30 days; the product page recommends recalibration every two weeks under regular use
• TruRead Mode: Records stabilized readings every 7 seconds and displays average, minimum, and maximum values
• Display: Three-color backlit LCD — white for measurement, green for calibration, and red for errors
• Waterproof Rating: IP67; protected against dust and temporary immersion, but not intended for continuous submersion
• Power Supply: Four AAA alkaline batteries
• Power-Saving Feature: Automatic shutoff
• Compatible Applications: Nutrient reservoirs, fertigation lines, hydroponic systems, coco cultivation, recirculating systems, and drain-to-waste runoff checks
• Included Accessories: GS3 meter, 50 mL bottle of 2.77 EC calibration solution, four AAA alkaline batteries, and lanyard
• Warranty: 2 years for the meter and 1 year for the probe
Key Advantage: The Apera GroStar GS3 combines EC, dual ppm scales, and temperature measurement in one portable instrument. Its replaceable titanium-alloy probe reduces the need to replace the entire meter when the sensor reaches the end of its service life. The dual ppm scales accommodate nutrient programs using different EC-to-ppm conversion factors, while TruRead mode helps growers compare readings across multiple reservoirs and irrigation zones.