Iran develops advanced Phytotron for precise plant growth control

An Iranian knowledge-based company has successfully designed and manufactured a specialized tissue-culture growth chamber, known as a phytotron, providing controlled environmental conditions for plant growth and tissue-culture experiments in research centers, universities, and biotechnology and agricultural industries.

The growth chamber precisely controls temperature, relative humidity and light intensity to create a stable environment for plant samples. Its design also allows the distance between the light source and the plants to be adjusted as the plants grow taller, ensuring consistent lighting conditions throughout the growth cycle.

The system can also monitor and control the concentration of various gases inside the chamber. Among its most widely used capabilities is carbon dioxide (CO₂) control, with concentrations adjustable from 1,000 to 5,000 parts per million (ppm).

The performance of a growth chamber depends on two key indicators. The first is the resolution and accuracy of temperature and humidity display and control. The device's display typically provides a resolution of between 0.3 and 0.5 degrees, reflecting the control precision at the location of the sensor.

The second indicator is the uniformity of temperature and humidity throughout the chamber and across the sample-storage shelves. The smaller the difference between measurements recorded at different points inside the chamber, the higher the system's performance. In this system, the maximum deviation in measured temperature at different points inside the chamber is approximately one degree Celsius.

An appropriately designed air-circulation system, along with precise control over the speed and flow rate of circulating air, also contributes to maintaining uniform environmental conditions and improving the system's accuracy.

After being designed and manufactured at the company's factory, the tissue-culture growth chamber is transported to the installation site in separate, disassembled sections. Installation and commissioning take approximately three days.

The installation site must have a level, ceramic floor. The use of large-format ceramic tiles is preferred to minimize the number of floor joints. A drainage route in the floor, in accordance with the installation drawings, is also recommended. The system requires a three-phase power supply with neutral and standard grounding connections.

The chamber's body is made of polyurethane-foam sandwich panels and has a useful volume of approximately 19,000 liters. It features shelving on both sides, with each shelf consisting of three levels. Each level is equipped with an independent airflow system beneath the samples.

The system's light intensity can be adjusted from 5,000 to 10,000 lux, while light intensity can also be reduced by switching off part of the lamps.

The system is controlled through a color touchscreen and can be programmed with up to 10 programs, each containing up to 10 stages. Other features include data recording and storage, computer connectivity, USB data storage, event logging, multi-user access and photoperiod-cycle control.

The growth chamber can control temperature from 4 to 45 degrees Celsius, with a resolution of 0.3 degrees and an accuracy of approximately one degree Celsius throughout the chamber. Relative humidity can be controlled from 40% to 95%, with an accuracy of approximately 3%.

The system uses a PT100 temperature sensor and a transmitter-type humidity sensor. It is also equipped with an audible alarm for temperature deviations, a high-limit mechanical thermostat and a telephone alert system that notifies operators when faults occur.

The chamber's refrigeration system uses direct expansion (DX) technology, while an integrated humidification system helps maintain stable environmental conditions.