NL: Cygnus Greenhouse Control

For more than 30 years Hotraco has been manufacturing and supplying control systems, which provide both reliability and excellent value to their products. The experience gained in combination with the latest technology, provides a guarantee for state-of-the-art Hotraco products.

The CYGNUS-CO2 is a computer which is suitable for greenhouses to control on/off heating and guard temperature, relative air humidity and CO2 level. The computer can be set with day / night time option incase need different settings are required.

If needed, extra CO2 can be produced by the heating unit when CO2 level becomes too low during the day. When CO2 level and / or temperature becomes too high, the windows can be opened or ventilation can be switched on.

Also it is possible to control the humidification when a humidity sensor is connected to the CYGNUS-CO2. At a low relative air humidity, the humidifier can be switched on, or when it gets to high extra ventilation can be applied.

Furthermore, the CYGNUS is provided with an alarm contact which activates an alarm when temperature, CO2 or relative humidity exceeds set values. The control communicates with clear language independent symbols that immediately make sense to the user.

Sources:
FreshPlaza.com
Hotraco Horticulture

Instrumentation enabling study of plant physiological response to elevated nighttime temperature

Global climate warming can affect functioning of crops and plants in the natural environment. In order to study the effects of global warming, a method for applying a controlled heating treatment to plant canopies in the open field or in the greenhouse is needed that can accept either square wave application of elevated temperature or a complex prescribed diurnal or seasonal temperature regime.

The current options are limited in their accuracy, precision, reliability, mobility or cost and scalability.

Results: The described system uses overhead infrared heaters that are relatively inexpensive and are accurate and precise in rapidly controlling the temperature. Remote computer-based data acquisition and control via the internet provides the ability to use complex temperature regimes and real-time monitoring.

Due to its easy mobility, the heating system can randomly be allotted in the open field or in the greenhouse within the experimental setup. The apparatus has been successfully applied to study the response of rice to high night temperatures.

Air temperatures were maintained within the set points + 0.5 oC. The incorporation of the combination of air-situated thermocouples, autotuned proportional integrative derivative temperature controllers and phase angled fired silicon controlled rectifier power controllers provides very fast proportional heating action (i.e.9 ms time base), which avoids prolonged or intense heating of the plant material.

Conclusion: The described infrared heating system meets the utilitarian requirements of a heating system for plant physiology studies in that the elevated temperature can be accurately, precisely, and reliably controlled with minimal perturbation of other environmental factors.

Author: Abdul MohammedLee TarpleyCredits/Source: Plant Methods 2009, 5:7