Multi-Function Optical Power Meter with VFL K-535

• Four jobs, one instrument: the power meter reads the level, the built-in red light proves the fiber, the RJ45 tester checks the LAN run, and the LED lights the cabinet — the technician carries one unit up the pole or into the plant room, not a bag of single-purpose testers
• Two range versions cover both ends of the work: -70 to +6 dBm for loss-heavy FTTH drops after big splitters, and -50 to +26 dBm for transmitter-side and CATV levels that would saturate a sensitive meter
• The VFL is a real locator, not a token LED: 650 nm at 2, 10 or 30 mW as ordered, steady or blinking, so a break glows through the jacket at the splice tray and a macro-bend shows itself along the drop
• Seven standard wavelengths (850–1625 nm) with wavelength memory — the meter wakes on the wavelength you used last, and the screen shows wavelength, nW and dBm together, so linear and logarithmic readings never need mode-hopping
• Honest field numbers: ±0.15 dB uncertainty, user calibration and user zeroing, so a crew can keep the unit true against its own reference source and record readings that stand up at acceptance
• Rechargeable lithium power with over 120 hours of working time and USB charging from a laptop or power bank — no AA stock to manage, and the flip-out stand props the meter on the cabinet shelf while both hands work the patch field
• Private labeling made to your requirements — labels with your logo, part numbers and barcodes on the inner boxes and outer cartons, ready for your warehouse

Start with the power meter. Set the wavelength to the service being tested — 1490 nm for a PON downstream, 1310 nm upstream, 1550 nm for overlay — and read the level at the ONT or the closure. The display carries the wavelength, the linear power in nW and the dBm figure together, so a low reading can be judged in both scales at once. If the level is out of budget, zero the meter on your reference source and use the dB reading to walk the loss back through splitter and splices.

Then prove the fiber itself with the red light. The 650 nm source launches into the same run; at a break the light spills visibly through the jacket, at a tight bend it leaks along the bend, and at the far end it confirms you are holding the right fiber among forty identical yellow cords. Steady mode for end identification, blink mode when several fibers in a tray need telling apart.

The RJ45 sequencer covers the copper half of the install: plug the run in and the 1–8 indicators walk the cores in order, exposing split pairs, crossed cores and dead pins that pass a casual link-light check. On combined fiber-and-LAN visits — most FTTH activations — that is the difference between one visit and two.

The rest is working comfort that adds up over a day: an LED light for the inside of closures, a backlight that turns itself off, a battery that runs a month of visits between USB charges, and a stand that holds the display at reading angle. Keep the port cap closed between tests and clean the connector before every reading — with four tools in one housing, the port is the one part everything depends on.

• One K-535 multi-function optical power meter
• USB charging cable
• User manual