This project is intended as a teaching medium air conditioning system and simulation of air conditioning system problems. Some of them have been modified to suit their teaching needs. Arduino microcontrollers are used to control the system. By starting the study of the air conditioning system thoroughly. The microcontroller is written to control the operation of devices like the air conditioning system when the system malfunction. It will be used to analyze the problems of air conditioning. The experimental set will display the voltage and current. The connection points of the air conditioning problem analysis. When the symptoms are bad. The analyst can solve the problem by connecting or pressing the button of the device. The results of the project. The test will measure the difference of the air conditioning unit. And read the amount of current and volume in the system. To diagnose abnormalities and choose a solution to the problem from the kit system that can be displayed to solve the problem that the analyst was correct or not with the LED status light. Based on the performance test a demonstration kit for the demonstration of efficiency of the air conditioning system was provided to 10 experienced air conditioning technicians. 80s of issues. The reliability of the demonstration set and the efficiency of the simulator case study of the electrical system in air conditioning systems is acceptable

Nowadays the measurement technologies are continually growth in advanced. These can be seen in the developed and developing countries that research and develop the products which support the consumer behavior and/or country economy ic growth. However some advanced products are very expensive such as pH meter. Therefore this thesis develops the pH meter which allows the acid-base test of the water and it can be supported the agriculture. The proposed pH meter is included the pH pen sensor temperature sensor water level sensor. The proposed meter can measure the acid-base of the water by sending SMS alert signal via GSM module to the mobile phone of the farmer. As can be seen this thesis can prevent and solve the effect of the high acid-base of the water that possibly flows into the agriculture farm via using SMS alert signal of the mobile phone of the farmer.