Dendrometer for stem

Dendrometer Nondestructive Absolute Linear MIJ-02LMS S-size (For sample size of dia1.5~23mm)


Diurnal variations in the thickness of the inner bark of tree trunks in relation to xylem water potential and phloem turgor

Dendrometers measure daily changes of trunk or stem caused by construction factors such as photosynthesis, transpiration, and sapflow; and also by hypertrophy factor which occur by the water storage during night time from root to trunk. Measuring annual changes is same as measuring speed of secondary growth and carbon fixation. Also it helps to analyze the data of the mid-term phenomenon that will change weekly from excess water stress.



・High temporal resolution, High resolution, unattended measurement

・Small sized target: measurement range φ1.5~23mm

・Avoid the thermal characteristic of potentiometer by Using ratiometric output

・Minimum friction help to setting low spring constant


Dendrometer MIJ-02 LMS

We recommend our Dendrometer MIJ-02 LMS to researchers by following reasons.

・Response to every single environmental changes with high time resolution, high resolution and no human effort.

・Thin branch and stem (between φ1.5mm and 23mm) can measure in a green way.

・Provide accurate measurements

The purpose of developing non-destructive dendrometer is because thin plants have less destruction resistance. Sample cross section will be narrowed from 3 directions of 120°division that mean offset placement of fastening part to samples. In other words, it  minimizing the sample stress from equipping instruments. This stress-free structure has one more advantage that is the sensor will not take time to fit to the sample; thus, it is possible to acquire the valid measurement data right after mounting the sensor to the samples. Generally, trunk or stem will change ± several dozen µm but MIJ02-LMS dendrometer can measure tiny changes, so we set the measurement resolution less than 1 um. It depends on the resolution of data logger but generally it can gain the data with  less than 0.01um resolution. (0.00911um/0.01mV.) Annual change of tropical rain forest will grow diameter direction around 10mm per year and only a few mm per year in temperate environment. Measurement range of LMS is φ1.5mm~23mm which could be enough to measuring thin sample. As annual changes, individual carbon fixation and production from individual sample will be the direct index that will be able to lead estimation of whole canopy value.

Figure1. Orange Sapling Stem growth (Click figure for enlarge)

Measured Period: May 11 to July 31
Above graph shows how Orange sapling stem growth.
As you can see there is no dramatic or rapid changes occur before harvesting fruit,
after fruit harvested the stem showed rapid growth.
Sapling is thin so dendrometer for tree cannot measure thin sample but MIJ-02 LMS
can measure thin target growth changes in micrometer.

Equipment used for this measurement: MIJ-02LMS TypeII & MIJ01 Data Logger


Product MIJ-02LMS Type2 (Sensor only)
Range  φ1.5mm~23mm
Output Ratiometric (eg: When preheat 5V then output full scale is also 5V)
Resolution 0.911um/mV
Regression Equation (Output) dr=11000*(Vout/ Vpre) / ( 1+SQR2 )
dr: Radius displacement, Vout: Output mV, Vpre: Preheat Voltage mV, SQR: Square root
Preheat 5VDC (<1mA at 5VDC)
Withstand Voltage <18VDC
Pin Assignment Brown: preheat
Blue: Output voltage Black: common

(Preheat GND and output voltage GND are shared)
Sliding Resistance <0.3N
Spring Constant Standard (for wood) 0.3N/mm, Medium (for plants without wood)0.1N/mm
Linearity ±1%
Thermal Characteristic <-0.126um/DEG
Waterproof IP67
Size Length:133mm  (When measuring max diameter 23mm)
Weight  42 g (Including hummer head stay; Not including Cable)
Supplied MIJ-02 LMS
NITTO EPTSEALER 50cm (Used for Mounting Hummer head to plant stem)
Cable Tie ×4

Parts List

MIJ-02 LMS LMS sensor, Ept sealer 50cm, Cable tie ×4
Standard Cable 2m Cable with IP68 M12 connector 2m
Standard Cable 5m Cable with IP68 M12 connector 5m
Standard Cable 10m Cable with IP68 M12 connector 10m
5m Cable extension connector both ended  Extension Cable with IP68 M12 connectors 5m
10m Cable extension connector both ended  Extension Cable with IP68 M12 connectors 10m
Waterproof Logger MIJ-12 Waterproof 1ch Logger
MIJ-01 Data Logger 8ch data logger (higher resolution)