Dendrometer MIJ-02 Absolute Circumferential

Dendrometer MIJ-02 Type II Absolute Circumferential Rotary


  • Wire typed dendrometer can measure immediately after set to plant.
  • Wire position close to stem (5mm distance), so that be able to measure absolute value
  • Pulley diameter: 37mm. Range of electrical and mechanical rotation angle:90°. These combination lead wide measurement range of 29mm.
  • Easy operation by equipping wire stopper
  • Ratiometric output lead to avoid potentiometer thermal characteristics

What is dendrometer ?
Dendrometer is sensor that help researcher, growers, and forester to measure the growth of plants. Dendrometers are mostly used by researchers to measure the growth of a stem, trunk, branch, roots or fruits for long term observation.
Very ancient type of measurement is by using tape or band which  wrapped around the trunk of a tree. This kind of measurement takes time and it will not give us exact result and also researches need to go to the place over the time, and record the plant growth daily, weekly or monthly.
To get exact result of plant growth, we need to avoid ancient type of measuring. 

Dendrometer MIJ-02 circumference
MIJ-02 Circumferential Rotary Dendrometer gives exact result by using electrical method.
Once MIJ-02 type II Circumferential Rotary Dendrometer connect to data logger, it will give daily, monthly, and annual plant growth result in μm unit.
The advantage of MIJ-02 is w
ire position will be close to stem (5mm distance), that will lead  giving  absolute value of plant growth. 

Figure 1. Quercus myrsinifolia Growth

Figure 1 shows how Quercus myrsinifolia grown from Apr  9 to August 18.
The dimension was 88.87 cm2 at begging of measurement and it increased to 102.04cm2 which means that the stem get thicker.  This can calculated as percentage, the result was 14.8179%  thicker from started measurement.
For more detailed calculation can be done and also from the result user can be estimate the how carbon fixation value moved.
We converted dimension to cm but as figure shows stem growth is in micrometer.

Equipment we used for this test: MIJ02 Circumferential Rotary Dendrometer & MIJ12 waterproof Logger

We suggest MIJ01 to user who want to see more tiny changes.


Standard Model MIJ-02 TypeII/W2.0
(Wire:1 meter; If the sample need more length please inform us, you can extend wire optionally)
(For waterproof connector cable please order as you need and specify the length)
Measurement Range 29059.7um
Output Ratiometric
(eg: when preheat set 5V then full scale of output will be 5V)
Resolution Depend on data logger
(5.81194um/mV, Using MIJ-01 less than 0.1um, MIJ-12 less than 5.8um)
Regression equation
(dL: displacement (um), Vout: voltage output, Vpre: preheat voltage
(MIJ-01: Input dL=29059.7*X001/5000 to PVS) 
Preheat 5VDC(1mA at 5VDC) 
Withstand Voltage <18VDC
pin assignment Red: preheat, White: output voltage, Black: common
(Preheat GND and output voltage GND are shared) 
Sliding resistance 0.03-0.15Nm (Measured value range  0-29mm)
Wire thermal characteristic Thermal expansion coefficient 17.3×10^-6/DEG 
Waterproof IP65 (Potentiometer part)
Operating Temperature -40~100℃ (it may frozen but will not destroyed)
サイズ W:50mm H:51mm L:73mm (Not including cable)
重量 110g (Not including 2 meter cable, fixing screws, 2 meter wire)
プーリ回転角度 90 degree (Both electrical, mechanical)
Holes (for fixing screw) 4 holes (φ4)
Screws Potentiometer stopper screw: M4-10(Hex hole 3.0mm)
Wire stopper screw: M2-6(Hex hole 1.5mm)
Waterproof connector standard CL07D03M(plug) main body side
CL07D03A(socket)2 meter cable side
  • ・1 meter wire (wire extension option 1m ~)
    ・2 Fixing screw SUS410
    ・Mesh tube 1 meter for wire (If extend wire optionally the mesh tube will be same length as wire length)

    *Special Accessories: Hex wrench 3.0mm,&1.5mm(Free 1 set for 1 o