Thermo Scientific TruDefender FT, User Manual, Page: 12 / 56

10
TruDefender FT and TruDefender FTi User Guide Thermo Scientific
2 Scanning
The Keys to Getting a Good Scan
The FTIR light beam emerges from the center of the
sampling tip. Because the beam can only penetrate a
few microns into a sample, to get a good scan you must
ensure that sample materials are in very close contact
with the sampling tip.
The keys to getting a good scan are:
1
When scanning powders or solids, use the sample
crusher or
firmly press the instrument into the
material.
2
Center the sample material on the sampling tip. The
Best Practices table (see
page 11 ) shows proper
positioning for the most common scanning
situations.
3
When possible, grind powders to a fine and even
consistency.
Whenever possible, use the sample crusher to scan
powders. The sample crusher exerts the firm and
constant pressure that is necessary to ensure good
contact.
TruDefender FT generally displays results in less than
30 seconds. Scans may be prolonged or may not
finish if:
• The sample material is not in close contact with
the sampling tip.
• The sample material interacts little or not at all
with infrared light (for example, pure elements).
TIP
Dilute solutions will return a positive match for
water because water strongly interacts with
infrared light.
Cleaning the Sampling Tip
Before every background check, clean the sampling tip
thoroughly.
To clean the tip, scrub it with an alcohol wipe, then
allow it to air dry, or wipe it with a clean paper towel or
cloth. If the tip is visibly dirty, wipe off as much of the
material as possible before scrubbing the tip with an
alcohol wipe.
If the sampling tip is contaminated with an oily
substance, scrub it with mineral spirits or paint thinner.
TIP
In very cold weather, liquid from the alcohol
wipe may freeze on the sampling tip and cause
inaccurate scan results. To prevent this, remove
any frozen residue by scrubbing the sampling tip
with a paper towel or cloth.