These two carbon dioxide detectors are helpful in evaluating indoor environmental conditions. The CompuFlow 8610 uses an internal NDIR sensor. One button operation allows easy stopping and starting of sample measurements. After a reading is complete, the minimum, maximum and average of the sample can be reviewed on the display screen. The better model, the 8650, is a more sophisticated instrument. It also measures temperature, humidity, dew point and wet bulb with one probe. It also functions as a data logger, storing up to 10,000 sample points and has the ability to calculate the percentage of outside make up air.

Alnor Instrument Co., 755 N. Linder Ave., Skokie, IL 60077; 800/424-7427 or fax 847/677-3539.