QTH10(/M) Quartz Tungsten-Halogen Lamp Chapter 3: Description
Rev I, May 23, 2019 Page 3
Chapter 3 Description
3.1. Product Overview
The QTH10(/M) Quartz Tungsten-Halogen Lamp offers stable output and broadband, incoherent illumination in the
visible and near-IR portions of the spectrum. It is a general-purpose lab tool with several convenient features,
including a heat sink, internal SM2 (2.035"-40) threading for compatibility with our Ø2" lens tubes, and an 8-32 (M4)
tapped hole for compatibility with our Ø1/2" posts. Two externally SM2-threaded end caps and a condensing lens
(item # ACL5040U) are included. The front end cap (item # SM2CP2) has a knurled edge that allows it to be
removed by hand, while the rear end cap requires the use of the SPW801 spanner wrench. Note that the unit should
not be operated with the rear end cap and optic removed.
3.2. Mechanical Description
The QTH10(/M) has a 10 W, 12 V quartz tungsten-halogen bulb in the middle, an ACL5040U condensing lens on
one end, and an SM2-threaded end cap on the other end. The housing is compatible with our TR series posts.
Internal SM2 threads on both sides of the housing permit different lenses, lens tubes, or other SM2-compatible
optomechanics to be attached.
The halogen bulb has a G4 2-pin base. By loosening a setscrew behind the end cap with a 0.05" (1.3 mm) hex key,
the bulb height may be adjusted.
3.3. Power Supply
The QTH10(/M) requires a 12 VDC power input. We recommend using the universal AC/DC power supply that is
included with the unit for best performance.
3.4. Bulb Alignment and Replacement
Alignment Notes
For the best imaging quality, the filament should be oriented perpendicular to the optical axis. To achieve this, use
a 0.05" (1.3 mm) hex key to loosen the setscrew holding the bulb in place. Looking down the optical axis of the
lamp, rotate the filament to be parallel to the optical axis, then back to perpendicular. This is a clear way to determine
the filament’s alignment.
In addition, for high imaging quality, the optical axis should go through the center of the perpendicularly oriented
filament. The use of an alignment plate, such as Thorlabs’ LMR2AP for SM2 Lens Tubes, will help determine
when the image is centered.
Bulb Replacement
We strongly recommend the use of gloves (such as latex or cotton gloves) when replacing the bulb in order to
prevent skin oils from being deposited on the glass.
1. Remove the power cord from the AC outlet.
2. Unthread the SM2 end cap. Allow sufficient time for the unit to cool. CAUTION: Bulb and surfaces may be
extremely hot!
3. Loosen the setscrew with a 0.05" (1.3 mm) hex key and pull the socket out of the housing.
4. Remove the bulb from the socket and insert the new bulb into the socket. Press firmly to ensure that pins
are fully seated.
5. Insert the socket back into the housing. Align the filament, then tighten the setscrew.
6. Thread the SM2 end cap back onto the housing.
