Efficient, high yield production of low loss, high bandwidth optical Fiber for telecommunication demands precise measurement and control of preform temperature during the various deposition processes employed.

The temperature of the preform in the burner zone, where the deposition takes place, is one of the critical control parameters which determines Fiber strength and transmission quality.

Measurement Problems The deposition process can be accomplished in various ways i.e. Inside vapor Deposition (I.V.D.P.), Outside vapor Deposition (O.V.D.P.), Modified Chemical vapor Deposition (M.C.V.D.).

The vapor Deposition Thermometer (VDT) must be able to sight precisely onto the rotating preform and avoid the effects of the flames, as the burner is traversed along the lathe.

Accurate surface temperature measurement can only be achieved using dedicated non contact radiation thermometers such as the LAND VDT.

Over twenty years of experience in this application has shown that thermometers operating in the waveband 4.8 to 5.2µm are the most suitable.

In this waveband, the preform is opaque and the measurement unaffected by the flames.
An accurate sighting facility and small target capability is given by focusable 100:1 optics.

Individually calibrated thermometers are available with traceability to National Standards. UKAS or NIST Calibration certificates are available.

Features

• Focusable, through-the-lens sighting - optional laser targeting is available
• Wide range of highly effective mounting accessories
• Rugged, flexible, modular design
• Accurate, reliable, drift-free measurement
• Industry standard outputs to suit any process monitoring, recording or control system