13
2.7 PRETEST TYMPANOMETRY CHECKS
For your convenience, a test cavity is provided with your TM 262
TM
Auto Tymp
TM
. This test cavity enables you to quickly verify the proper
calibration of your unit. Welch Allyn, Inc. strongly recommends that
you make this quick check a part of your daily routine.
2.7.1 Calibration
To initiate the quick check, select the Tymp only mode and insert
the probe
(without a tip on it)
into the 0.5 cm
3
opening on the test
cavity. See Figure 2-12.
NOTE
Since the TM 262 is designed to start automatically, it is important that the
probe is inserted as quickly and as smoothly as possible. During the calibra-
tion check, the probe must be held carefully and without movement. Do not
place the probe on the same counter as the instrument or any moving object
during this check, as mechanical noise will be picked up by the probe and
interfere with the calibration check.
FIGURE 2-12: Test Cavity
The calibration check will start automatically if the probe has been in-
serted into the cavity properly. This is confirmed by the green lamp
changing from blinking to a steady condition. If the orange lamp is illu-
minated, the probe is not properly positioned within the cavity so that
a large pressure leak exists. If the yellow lamp is illuminated, the probe
tip has been occluded. In either case, remove the probe and wait for
the blinking green lamp. Insert the probe once again. Clean the probe
tip if necessary (see Section 3.2).
0.5 cm
3
2.0 cm
3
5.0 cm
3
TYMP
