The TDP pin-type plant stem flow meter is mainly assembled from the CR1000 data logger and TDP probe sensors. It is used to study the water use status of trees by measuring the speed of plant stem flow (unit: g / h or kg / h).
Based on Granier thermal diffusion principle, the TDP probe sensor’s two thermocouple probes are inserted directly into the sapwood of the tree. The upper probe contains an electric heater, and the lower probe is used as a reference. The temperature difference dT between the two probes will be measured. According to dT and dTm while no stem flow, the Granier model is applied to measure the stem flow rate per unit time, and then the stem flux will be obtained by combining sapwood area.
The CR1000 data logger is installed in a weatherproof enclosure, where the voltage regulated module with LED display is embedded. PC400 software realizes Programming, communication and reliable data exchange between PC and CR1000 data logger is completed by PC400 software.
The quick connector of the extension cable is waterproof, so the whole system can be normally used under extremely harsh conditions. However, the quick connectors of many similar products or even imported equipments are poorly waterproof. When used in a humid or rainy environment, such quick connectors are prone to water ingress, which will lead to corrosion or breakage of the core of the cable and cause the instrument to not be used normally.
Main features:
The data logger and probes are all imported from the United States, and are rigorously calibrated before leaving the factory to ensure the measurement accuracy.
Excellent field waterproof performance, the probe is equipped with a waterproof connector, which is better than similar imported products from abroad.
Can be equipped with other sensors, such as stem growth sensors and weather sensors.
Data logger:
Model: CR1000(or other models)
Memory capacity: 4MB, up to 1,000,000 data values, or 500 days of recorded
values using 12 TDP probes simultaneously
Built-in program: measure raw data and calculate stem flow, with automatic zero
adjustment at night and power saving mode
Accuracy: ± 0.03 ℃
Heating voltage regulator: two voltage regulators (1.5 ~ 11 V), 5 A per
channel, with input and output voltage display module
Cable length: freely customized according to actual needs
Interface waterproof rating: IP68
TDP probe:
TDP probes are available in a variety of different length models, such as
TDP-10, TDP-30, TDP-50, etc. The length of probe is 10mm, 30mm, and 50mm respectively.
An appropriate probe model should be chosen according to the thickness of the
measured stem.
Probe model
Probe length
(mm)
Probe diameter
（mm）
Probe spacing
(mm)
Thermocouple number
Power
(W)
Heating resisitance
(Ω)
Operating voltage
(V)
Signal output
(μV/℃)
TDP-10
10
1.20
40
1
0.08~0.12
26
2.0
40
TDP-30
30
1.20
40
1
0.15~0.20
50
3.0
40
TDP-50
50
1.65
40
1
0.25~0.30
77
5.0
40
TDP-80
80
1.65
40
2
0.45
122
7.0
40
TDP-100
100
1.65
40
3
0.5~0.6
144
8.5~9
40
010-53510519
