The Fluke Networks TS25D telephone test set, available with various line cord connectors to suit specific applications, is designed for indoor testing of telephone lines to detect dial tone and polarity, make and receive calls, and indicate line voltage and current.
It has a one-way, adjustable-volume speaker for hands-free listening during testing and a built-in analog tone generator that sends a signal through wires for locating and tracing wires with a probe (sold separately); monitors lines without disrupting service and remains off hook if data is detected; and stores up to ten 23-digit telephone numbers which can be speed-dialed via the keypad.
The test set provides tone or pulse operation, detects caller ID and call-waiting ID, and tests continuity to detect short circuits.
It has two basic modes of operation: talk mode for off-hook operations including verifying dialing and receiving calls, and monitor mode for on-hook operations including checking for an idle line, listening for line noise, measuring DC voltage on the line, and capturing DTMF (dual-tone multi-frequency) tones to check for proper signaling.
The keypad has 12 standard dialing keys including star and pound, and function keys to redial numbers, adjust speaker volume, and navigate menus, among other functions. The LCD displays icons for test status such as indicating normal or reversed DC polarity, and displays readings of voltage from 0 to 250 VDC when on-hook and current from 0 to 110 mA when off-hook. The test set can be programmed to turn off automatically after 30 or 60 minutes (default setting is 60 minutes) of inactivity to conserve battery life.