Dickson Temperature Chart Recorder. S/N: 9275259. Two-pen recorder with touchpad controls and digital display. Uses chart C417, 8", (-20/120 7D). Calibrated: 10 -02. Input: 120 VAC, 23 watts, 60 Hz. Output: 6 VDC, 750 milliamps. The DICKSON Model THDx is a microprocessor controlled recorder with remote sensing capabilities, super accuracy, and user selectability of both temperature ranges and recording times (1, 7, and 31 days). Overall dimensions: 13 in. L x 3-1/2 in. W x 10 -1/2 in. H.