Viable for stabilizing column temperatures at or near room temperatures for repeatable results, the EchoTherm Model CO50 programmable HPLC column chiller/heater has a temperature range from +4°C to +100°C, readable and settable to 0.1°C. PID control software regulates temperatures to ±0.2°C, even at ambient. A Peltier-based system, the CO50 has a five-program memory consisting of 10 steps per program and the ability to repeat any program from 1 to 99 times automatically. It holds columns up to 30-cm long by 0.25 or 0.375 inches in diameter within mounting clips. Other features include an RS-232 I/O port for controlling the unit with a chromatograph, an injection counter, 30-day timer with user settable Auto-Off, and a chamber drain for spills.