GRAIN MOISTURE METER Plant Stress Detection with Fv/ Fm Fv/ Fm - A Measure of Maximum Potential Quantum Efficiency Fv/ Fm is the most used parameter for plant stress detection in the world,  and it is a robust way to detect stress that affects photosystem II. General Specifications Display : Color Graphic Display Storage Capacity Up to 160,000 measurements. Up to 32 traces can be stored with a one data file name. Hundreds of traces can be stored in multiple data files, with different names. Battery : NiMH battery pack with a battery life of 8 hours between charges. Digital output: USB port Dimensions: 18cm, 7 cm, 6cm.           Weight: 1.25 lbs. , with carrying case and accessories - 4 lbs. Carrying case: Included std. Case dimensions: 36cm, 28cm, 15 cm Modulated Fluorometer  Saturation intensity : 600- 6000 umols set from 10% to 100% Saturation light source : Array of red LEDs 660 nm. Modulated light source : red 0.2 to 1.0 :mols. Detection method : Pulse modulated Detector and Filter : Pin photodiode with 700-750 nm band pass filter Test duration : 0.1  seconds to 1.5 seconds. The default saturation pulse duration is set at 1.0 second; however, the software takes a rolling eight point 25 ms average to determine F ,  and F , making it idea for both algae and land plants.  Modulated light adjustment : manual adjustment from 30% to 80%