dendrometer for fruits

LVDT Fruit DendrometerA series of absolute displacement sensors provides recording both size and growth rate of intact rounded fruits in three diameter ranges within 7 to 160 mm.

Two phenomena affect fruit diameter. These are growth and internal water content. The growth component is usually dominant. At the same time, in some cases, the fruit may loose water that is manifested in deceleration of growth rate or even shrinkage of the fruit. It may be a result of water stress, lack of light, or another limiting factor.

Thus, the FI-type sensor allows investigating effect of irrigation rate and other environmental factors on both water balance and growth of fruits. Another exiting application of the sensor is monitoring of harvested fruits during storage.

The FI-type sensor consists of an LVDT transducer mounted in a special clip and a DC powered signal conditioner.

The probe is connected by a standard 1-meter cable to the waterproof box with the signal conditioner inside.

The output cable length should be specified in the order if required.

Original parallelogram design of moving arms provides firm and straight positioning of the sensor’s flaps on a fruit under study.

FI-LM (large), FI-MM (medium) and FI-SM (small) models have different clips for providing three measurement ranges: 30 to 160, 15 to 90 and 7 to 45 mm, respectively.


video – a FI-MM dendrometer installed on a mango:


video – the dendrometer field monitoring system



feature specification
Measurement Range FI-LM: 30 to 160 mm | FI-MM: 15 to 90 mm | FI-SM: 7 to 45 mm
Sensitivity (mV/mm) FI-LM: 15.4 | FI-MM: 26.7 | FI-SM: 52.6
Noise < 1 mV w/filter, 1 kHz cutoff
Resolution FI-LM: 0.065 mm | FI-MM: 0.038 mm | FI-SM: 0.019 mm
Output SDI-12, RS-485, Voltage or 4..20mA
Supply Voltage 10 to 30 VDC
Power SD-5/6M: 1.5 W max | SD-5/6Mi: 2 W max
Operating Temperature 0 to 50 ℃
Temperature Effect < 0.02 % total stroke / ℃
Excitation Time 5 seconds
Cable length between probe and signal conditioner 1 m
Cable length between signal conditioner and data logger 5 m (standard) | maximum: 10 m for voltage sensors; 200 m for 4 .. 20 mA sensors




Fruit DendrometerDownload Fruit Dendrometer Manual


additional information

Dendrometers: multi-purpose sensors