Just as the cost of consumer electronics and computers keeps going down, so does the cost of industrial controls. Programmable Logic Controllers, single purpose temperature controllers, temperature and pressure sensors, etc. all continue to improve in quality and reliability at reduced prices.
On source for basic to medium-level controls is AutomationDirect at www.automationdirect.com. This company offers many solutions for PLC’s of different sizes, capabilities and purposes. It also offers many other single purpose controllers such as temperature controllers. AutomationDirect offers superb technical support for free. Their prices are virtually unbeatable.
A source for electronic sensors (themperature, pressure, humidity, etc.) to tie into these controllers is Kele at www.kele.com. Kele offers quality sensors at discounted rates.