User manual HANNA INSTRUMENTS HI 83900

[. . . ] 4 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 OPERATIONAL GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 · ACTIVATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 · INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Check that the rubber capillary is into the ceramic tip, then remove the plastic bag from the ceramic part and follow the activation procedure explained below. INSTALLATION Location · The selected location/plant for installing the lysimeter should be representative of the entire field. · For better accuracy and repeatability of results, install at list 3 couples of lysimeters (see below) per each area to be monitored. Operation · Place the lysimeter inside the root zone. It is suggested to install at least two lysimeters, one at the upper and the other in the lower layer of the root zone. · The recommended distance from the drip source depends on the soil type: sandy soil: 5 cm; medium soil: 10 cm; heavy soil: 15 cm. Important: NEVER TOUCH THE CERAMIC SENSITIVE PART WITH YOUR FINGER BEFORE AND DURING THE ACTIVATION PROCESS. ACTIVATION · Fill approximately 1/3 of the lysimeter tube with the supplied cleaning solution. · Draw the syringe piston all the way back and attach the syringe to the rubber capillary. · Close the tube with the rubber cap, open the finger clamp and push the syringe piston. · Pinch the finger clamp and wait until the solution seeps through the porous ceramic tip. Draw the rest of the solution from the sampler tube and dispose of it. · The lysimeter is now sterile, free of air bubbles and ready for insertion into the ground. · Keep the ceramic tip moist until the lysimeter is inserted into the soil. Protect it with a plastic bag. · Drill a hole in the ground at the selected location and insert the HI 83900, while pushing and rotating it around its axis. After the proper depth is reached, compress the surrounding soil, while paying attention that the soil is tightly in contact with the ceramic tip. 6 7 SAMPLE EXTRACTION Warning!Never operate the lysimeter in the following conditions: · immediately after irrigation, otherwise the extracted solution will be the irrigation water and not the soil solution. · before the irrigation water reaches the depth of the ceramic tip, because necessary tension can never be obtained if the sensitive tip is dry. · Sample extraction needs a vacuum of approximately -60 cb (centibar) to be created inside the sampler tube. Connect the syringe to the rubber capillary, open the finger clamp and draw the syringe piston all the way back (30 mL). Pinch the finger clamp and disconnect the syringe. To obtain a vacuum of about -60 cb (centibar), perform these operations once with the HI 83900-30 model, twice with HI 8390060 and 3 times with HI 83900-90. · Before drawing out the soil solution, allow a time interval which depends on the soil type. Tuff or sandy soil: 30 minutes Light soil: 1 hour Medium soil: 2 to 4 hours Heavy soil: 3 to 12 hours · To collect the soil solution, connect the syringe to the rubber capillary, open the finger clamp and the rubber cap, then draw the syringe piston all the way back (30 mL). · Hold the piston until all the solution is sucked into the syringe, then disconnect the syringe from the capillary and leave the finger clamp open. [. . . ] This can occurs when the lysimeter is positioned at a depth of 40-50 cm. · Water reaches the depth of the ceramic tip very slowly, also measured in days for very heavy or compact soils. In this case, the lysimeter should not be installed in low depths such as 50-60 cm. >>> Use the lysimeter in depths of only 15-30 cm. [. . . ]