Low-cost Temperature Controller Research Articles

Raspberry Pi and Sensor Networking for African Health Supply Chains

Many medicines in Sub-Saharan Africa lose their effectiveness along the supply chain. Some of the reasons are poor information flows, lack of temperature control systems as well as missing standardized processes including the measurement through performance indicators. Studies from the World Health Organization – executed in 70 countries – report that only 29% of these countries meet the minimum recommended standards for temperature control and levels. In order to meet these challenges, efficient and effective ways need to be found. Frequent power outages, low level of education of personnel and a high rate of warehouses without any ITinfrastructure need to be taken into account. This paper focuses on the usage of Raspberry Pis and Arduino (small, simple and low priced computers) in combination with sensor networking. An in-depth literature analysis as well as an onlocation inspection in Cameroon helped to detect the challenges African health supply chain managers face. The study of the possibilities of a Raspberry Pi in combination with Arduino and sensor networking is currently conducted in order to see if these hardware components could help to improve the cold chain challenges of high priced medicines (e.g. vaccines) in developing countries, e.g. in Sub-Saharan Africa. The objective of our research is to identify a fast, low-cost temperature control system in warehouses in developing countries and health supply chains which is easy to implement, to use, to maintain and works effectively (e.g. fast and reliable).

DESIGN OF A LOW COST TEMPERATURE CONTROLLER FOR HIGH TEMPERATURE FURNACES USED IN CRYSTAL GROWTH

Temperature plays a very vital role in proper growth of crystals and compound semiconducting materials. Temperature also affects the properties of the materials. Therefore, it is desirable to accurately monitor and control the temperature of the furnace used for Growth of different types of Materials. This paper focuses on the design and construction of a low cost temperature controller for high temperature laboratory based furnaces used for crystal growth. It can also be used for industrial furnaces. The design is based on microcontroller (IC PIC16F873A). In the circuit K-type thermocouple is used as a temperature sensor. Suitable instrumentation and signal conditioning circuit is developed to give desired electrical signal to the microcontroller which is equivalent to the actual temperature. The actual temperature is monitored continuously. Because different materials have different melting points, facility is provided to program different temperature profiles. When the device exceeds a preset temperature level, power output of the circuit is switched OFF, hence switching of the heating device (Furnace). The developed circuit is reliable and cost effective. It has good accuracy better than ±1oC.The overall performance of the controller is tested and found it perfectly functional.

Adaptive Temperature Control Systems Design

This paper presents an advanced low-cost temperature control system. The system takes the highest performance-cost ratio as its aim. It uses the low-cost 8-bit MCS-51 MCU and integrated temperature sensor to achieve the on-site control. A lower cost remote host computer can be used in this system. In the case of a relatively larger application, it can be expanded to a control system of master-slave distribution and utilize the computing and storage resources of the microcontroller. It realizes a wider range of temperature adjustment, and then put the state of the system into a database of the microcontroller to be ascertained later.

Low-Cost Temperature Control from 160 K to Ambient Temperature Using Liquid Nitrogen Evaporation

A low-cost temperature controller that allows variation from 110 K to room temperature of liquid, gas, or solid samples is described. The desired stabilized temperature is obtained within a few minutes by controlling the current through an electrical resistor immersed in a liquid nitrogen reservoir. The stability of the temperature ranges from less than ± 0.5 K at temperatures higher than 230 K to ± 1.1 K at 160 K. The maximum consumption of liquid nitrogen for cooling a glass photochemical reactor was less than 0.60 liters per hour at temperatures lower than 160 K, about 0.4 liters per hour at 160 K to 190 K, and decreases considerably over 200 K. A linear dependence of the temperature with a flow of evaporated gas was found (240–285 K). This device can be used easily in experiments that need low temperature regulation, involving gas–surface interactions, adsorption–desorption processes, heterogeneous atmospheric chemistry, thermodynamics of gases, and so forth.

A simple, low-cost temperature controller for NMR spectrometers

A simple, low-cost temperature controller for NMR spectrometers

High-precision low-cost temperature controller

A temperature controller is described, capable of maintaining the temperature of a properly constructed thermostat constant to within +or-5 mu K for an hour and 40 mu K for a week in the range from about 280 to 320K. It uses a thermistor as a sensing element in conjunction with a simple AC Wheatstone bridge. The electronic circuits of the controller, consisting of a lock-in amplifier, a proportional, derivative and integral regulator and a power stage, are built of low-cost, commonly available components. An extension of the temperature range of application is straightforward, but will lead to reduced accuracy.