An economical solid-state TDR with octal plug-in base, the 339 maintains excellent repeat accuracy despite wide voltage and temperature variations. even after long periods of down-time. Two models are available. Each has six dial selected ranges from fractions of a second to as long as 10 hours. Each model has a selectable on-delay or interval timing mode.
Wide Choice of Ranges: In addition to the short ranges expected of an electronic TDR, the 339 is also available with ranges as long as 10 hours. An unusually versatile timer, the 339 has six dial-selected ranges—from 0.3 sec to 3 hours or 1 sec to 10 hours—and provides dial-adjustable timing periods between 0.075 seconds and 10 hours. A single 339 model thus accommodates the needs of a wide range of applications, allowing the user to select easily and precisely—an appropriate range to permit optimum setting accuracy. The dial face automatically displays the selected range.
Cycle Progress Indication: The 339’s LED annunciator provides a unique and effective method of cycle progress indication. Off before timing, the LED blinks at an ever-increasing rate as the cycle progresses; once every 3 1/2 seconds during the first 10% of the cycle, twice during the second 10%, and so on. At time-out, the LED stays on constantly, pulsing at a high rate. (In the 1 and 10-second ranges, the LED is off before timing, steady on during timing, and pulsing on after time-out.)
High Accuracy: The 339’s timing circuit is not a simple RC circuit, but utilizes the sophistication of a proprietary integrated circuit that includes counting technology along with a stable oscillator to provide repeatable time delays.
Multiple Timing Modes: Every 339 can be used for either on-delay or interval timing operation. The timing mode is selectable by a switch on the 339A housing.