The SEMTECH® CAL module has 7 input ports to accommodate a rack of various calibration gases. The unit has 3 output ports; Purge, CAL 1, and CAL 2. These ports may be utilized with the SCS module, Sample Purge unit, and EFM4 module to perform calibration procedures, time alignment, and leak checks. The SENSOR Tech-Pro host software may be programmed to perform the automated zero/span operation at a set time. The CAL module may be mounted on a wall, tabletop, or strapped to a gas bottle.