After calibrating and testing with a known commercial spirit, this error was up to 5%. I would have agreed a few percent, but that was too much. I used to buy cheap refractometers and their error was less than now.
TDS water quality tester - TDS water hardness meter (portable digital salt meter for water analysis)
9 Review
π PH 1-14 Extensive Storage Testing Monitoring: Optimize Your Storage with Precise pH Level Monitoring
6 Review
Portable digital multimeter with sound continuity and thermocouple (electric tester) LTX DT-838
7 Review
Digital PH Meter Tester - Tiaoyeer Water Quality Tester With ATC, 0.01PH High Accuracy, 0.00-14.00 Measurement Range, 0.01 Resolution For Drinking Water, Aquarium, Swimming Pools, Hydroponic
8 Review
π Enhanced Precision with Backlit Professional Manometer for Differential Ventilation
6 Review
Portable Handheld Manometer π for Accurate Pressure Differential Measurement
5 Review
π Dioxide Controller for Digital Gas Monitoring
5 Review
π§ UEi Test Instruments DAFM3B Digital Multimeter
6 Review