Point dendrometers are high-precision measuring instruments with which changes in diameter (trunk, branches, roots) in the micrometer range (μm) can be recorded in a temporal resolution of minutes. This means that Transpiration-related changes in day-night diameters as well as the irreversible secondary thickness growth induced by new cell formation in the xylem and phloem over the course of the season can be measured. In general, plant-water relationships and growth rates can be quantified depending on (changing) climatic conditions. The point dendrometers generally consist of an O- or T-shaped (carbon) frame including anchoring system, depending on the diameter, as well as a sensor, the sensor head of which is pressed lightly against the surface of the measured object by a spring.All parts of such measuring devices are more or less sensitive to temperature. The absolute temperature sensitivity of the point dendrometer is <0.5 µm per ° C.The point dendrometers are powered by a 3 to 5 V DC power source and are compatible with almost all types of data loggers on the market.

The ZN12-O-WP is a point dendrometer with a ring-shaped frame, which is offered in different sizes to cover a wide range of small diameters (of trunks, branches, roots) from 1 - 8 cm.
The available diameters are:

• 100 mm (ZN12-O100),
• 80 mm (ZN12-O80),
• 60 mm (ZN12-O60).

Advantages

• No disturbances induced by temperature and humidity caused by deformation of the outermost layer of bark that is not living
• Components that are insensitive to temperature enable high-precision measurements in the μm range
• No influence of the measuring range by the anchoring system
• Easy to assemble
• Very robust and weatherproof material