OPERATION
Temperature Control
14 LDM-4990
CHAPTER 2
mount. Use a ½" open-end wrench to tighten the fittings. Use caution when tightening
the fittings to avoid damaging the threads in the 4990 fixture.
3 Connect 1/4" I.D. flexible tubing to each fitting and to a water source and drain.
Figure 2.8 LDM-4990 Water Connections
Nitrogen Purge
As the temperature within the LDM-4990 is driven to near ambient and below, the
problem of condensation around the laser device and mount becomes a concern.
This environmental problem has been addressed by the use of a nitrogen purge
system designed into the mounting fixture. This purge system ventilates the inner
cavity of the LDM-4990, preventing condensation on the laser diode and the
surrounding components.
To flow nitrogen through the LDM-4990, a 1/16" OD nipple is provided on the back
of the mount, (see Figure 2.9) above the laser current and temperature controller
connectors. Connect 1/8" OD plastic tubing on to the nipple and push over the
flare to prevent the tubing from disconnecting or leaking under pressure.
