Stem variation monitoring transmitter for crop moisture status

Abstract

The invention belongs to the technical field of agricultural water-saving irrigation and particularly relates to a stem diameter variation monitoring transmitter for the crop moisture state. The stem diameter variation monitoring transmitter comprises two parts, namely a probe and a processing circuit, wherein the probe comprises a displacement sensor, a probe bracket and a constant force spring bracket, a concave stretching movable support frame for fixing rolling constant force springs is fixed on a measuring push-pull rod of the displacement sensor, two same rolling constant force springs are symmetrically mounted at the right upper part and right lower part of the constant force spring bracket, and stretching ends of the two same rolling constant force springs are respectively symmetrically fixed on the upper side and lower side of the concave stretching support frame. According to the stem diameter variation monitoring transmitter, as being throughout maintained at optimal sizes due to the size of a force applied to a stalk by the measuring push-pull rod, the rolling constant force springs do not need to be adjusted until the whole measuring range of the measuring push-pull rod is compressed, and the influence of the growth of a plant stem to a stem diameter variation monitoring result is overcome; the processing circuit utilizes a nonconventional manner that the power is independently supplied to the displacement sensor by utilizing external high-precision voltage reference, so that the stability is good; the structure is simple, and the cost is low.

Description

Technical field: [0001] The invention belongs to the technical field of agricultural water-saving irrigation, and in particular relates to a transmitter for monitoring crop water condition stem variation. Background technique: [0002] The stem variation monitoring transmitter is used to monitor the slight change in the diameter of the crop stem. The slight change in the diameter of the crop stem refers to the shrinkage of the crop stem during transpiration and water loss during the day, and the root system absorbs water and expands at night, resulting in a change in the diameter of the plant stem. Minor changes. The slight change of crop stem diameter is closely related to the change of moisture in the crop body, and it can also reflect the change of external transpiration conditions and soil water supply capacity. In foreign countries, relevant experimental research on monitoring crop water status by using slight changes in plant stem diameter has begun in the late 1950s....

AI Technical Summary

Problems solved by technology

Different from other studies, Sato et al. used laser diameter sensors to monitor crop water status with stem diameter changes, because laser stem diameter sensors did not have the problem of plant stem growth using spring displacement sensors in other studies

The displacement sensor is clamped on the plant stalk by a spring. The pressure of the spring on the plant stalk is proportional to the displacement of the spring. With the growth of the plant stalk, the displacement of the spring increases, thus acting on the plant stalk. The pressure is gradually increased, resulting in a gradual decrease in the small changes in plant stem diameter (expansion and contraction), which seriously affects the monitoring results of stem deterioration

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