DC1 Circumference Dendrometer

The simplest model in the DC series, the DC1, is attached to the measuring object by the tension of the spring-loaded cable. The tension force is imparted tangentially, and the circumferential signal is recorded directly via the metal cable.

DC3 and DC4 are improved versions of the DC series. The tension force exerted by the sensor spring is transmitted to the measuring wire in radial, and not tangential (cf. DC1), direction. This patented, special design of the DC3 and DC4 dendrometers significantly improves the comparability of the measurement data from objects of different diameters. Additionally, this design ensures a consistently stable installation on objects with both small and very large diameter

Advantages

• Maximum stability against wind, snow, falling branches and fruits
     
• Easy and injury-free installation
  
  

Specific to the DC3 & DC4 models

• Suitable for all stem diameters (> 5 cm)
     
• Improved data comparability between measurements on tree diameters
     
• Exact measurements (even with very large trees)
  
  

Limits

• Not suitable for measurements underwater nor under snow cover
• Specific to the DC1 model   
• Measurement data between trees with very different diameters are usually not comparable.
• Measurement values on trees with increasing diameter may be problematic due to the decreasing contact pressure between cable and trunk surface.  
• Specific to the DC3 & DC4 models
• Raw measurement data must be converted to circumference in mm (Excel program available)
• The cross-section of the measurement object should be approximately circular

Technical data

Sensor model name
    

Circumference Dendrometer 1
Type DC1
    

Circumference Dendrometer 3
Type DC3
    

Circumference Dendrometer 4
Type DC4

Scope of application
Slow/average growth rates
Slow/average growth rates
Fast-growing

Suitable for diameter
5 – 32 cm
> 5 cm 
> 5 cm

Special features/limitations
Confined comparability with different trunk diameters
Comparability for different trunk diameters improved.
Comparability for different trunk diameters improved.

Measurement range
11 mm linear ≙ 11 mm circumference
25.4 mm linear ≙

circumference (diameter-dependent):
50 mm (at Ø 10 cm)
35 mm (at Ø 50 cm)
28 mm (at Ø 100 cm)
50.8 mm linear ≙

circumference (diameter-dependent):
107 mm (at Ø 10 cm)
80 mm (at Ø 50 cm)
65 mm (at Ø 100 cm)

Resolution
    
Data logger dependent e.g.:

CR300 series: 0.01 µm
Dendrometer logger DL18: 0.2 µm
Data logger dependent e.g.:
CR300 series: 0.03 µm
Dendrometer logger DL18: 0.5 µm
Data logger dependent e.g.:
CR300 series: 0.05 µm
Dendrometer logger DL18: 1 µm

Accuracy
   
Dendrometer dependent: max. ± 4.5% of the measured value (stable offset)
Data logger dependent e.g.:
CR300 series: ± (0.04% of the measured value + 0.3 µm)
Dendrometer logger DL18: ± (0.1% of the measured value + 0.45 µm)
Dendrometer dependent: max. ± 1.97% of the measured value (stable offset)
Data logger dependent e.g.:
CR300 series: ± (0.04% of the measured value + 0.6 µm)
Dendrometer logger DL18: ± (0.1% of the measured value + 1 µm  
Dendrometer dependent: max. ± 0.98% of the measured value (stable offset)
Data logger dependent e.g.:
CR300 series: ± (0.04% of the measured value + 1.2 µm)
Dendrometer logger DL18: ± (0.1% of the measured value + 2 µm)

Output signal 
Analogue, 0V to Vex (excitation supply voltage)
Analogue, 0V to Vex (excitation supply voltage) 
Analogue, 0V to Vex (excitation supply voltage)

Temperature drift of the sensor
< 0.2 µm/°C in the whole measurement range  
< 0.2 µm/°C in the whole measurement range
< 0.2 µm/°C in the whole measurement range

Temperature coefficient of the stem embracing cable wire
< 1.4 ×10-6/K
< 1.4 ×10-6/K
< 1.4 ×10-6/K

Linearity
< 1%
< 0.7%
< 0.5%

Operational conditions
Normal outdoor conditions, -25 to 70 ° C, 0 to 100% relative air humidity; unsuitable underwater and below snow cover
Normal outdoor conditions, -25 to 70 ° C, 0 to 100% relative air humidity; unsuitable underwater and below snow cover
Normal outdoor conditions, -25 to 70 ° C, 0 to 100% relative air humidity; unsuitable underwater and below the snow cover

Weight (sensor without cable)

13 g
37 g  
47 g

Power supply

Vex (! stabilized !) 0.5 to 10 VDC,

Power consumption max. 0.28 µWh per measurement

Vex (! stabilized !) 0.5 to 10 VDC,
Power consumption max. 0.28 µWh per measurement

Vex (! stabilized !) 0.5 to 10 VDC,
Power consumption max. 0.28 µWh per measurement

Material
Stainless steel and aluminium
Stainless steel and aluminium
Stainless steel and aluminium

Sensor cable length
5 m, extendable on request to max. 100 m
5 m, extendable on request to max. 100 m
5 m, extendable on request to max. 100 m