A penetrometer for finding compacted soil and how deep it lies. Press it into the ground and read the dial: green means good growing conditions, yellow fair and red poor. If the needle goes into the red and then drops back as the tip passes through, you've found a compacted layer. The shaft is marked every 7.5 cm so you can read the depth.
It comes with two tips, a small one for compacted soil and a large one for soft soil, each with its own scale on the dial. Start with the small tip. Test in early spring before sowing or in autumn before tillage, when the soil is moist: dry soil reads too high and wet soil too low.
Use the pointed tips with care, and don't push it into electric cables, water pipes or anything else buried. Wipe it clean with a cloth, keep moisture out of it, and store it dry, hung from the hole on the back. The dial is filled with silicone oil; a small air bubble is normal.
Specifications
Type
Soil compaction tester (penetrometer)
Dial
Green 0 to 14 kg/cm² (0 to 200 psi), yellow 14 to 21 kg/cm² (200 to 300 psi), red over 21 kg/cm² (300 psi)
