The new Pocket Colorimeter™ II Filter Photometer is a true go-anywhere instrument. It's lightweight and battery operated, suitable for extended field work or quick, on-the-spot process monitoring. The instrument has two channels in which measurements can be made. Each channel will accept a user-defined calibration curve. Up to 10 standards can be used to determine the calibration. The curve is generated by a point-to-point straight line segment between each standard used. Linear and non-linear positive or negative slope calibrations can be performed. A calibration curve may also be manually entered from the keypad if a previously determined curve has been made on the Colorimeter. At least two data pairs (concentration and absorbance) are required.