Device for determining the thickness of plant tissues

The invention relates to the study of material characteristics， in particular to devices for determining the thickness of plant tissues by the method of their puncture.The device， according to the invention， comprises a vernier caliper (1) on the base of the movable jaw (7) of which is fixed a cramp iron (2) with two coaxial threaded holes. A graduated indicator (4) is fixed in the first hole with a clamp screw (11) on the side of the cramp iron (2)， and in the second hole， the end of a spring (6) is fixed with a screw (3) and a nut (8). On the free end of the spring (6)， by means of a washer (9)， is fixed the sharp end of a needle (5)， the opposite end of which is connected to the graduated indicator (4). The needle (5) is placed with the possibility of moving in the hole of the screw (3) and in a through hole， made in the movable jaw (7) coaxially with the holes of the cramp iron (2).