Model 820 Technical Reference Manual
Taking a Measurement
5-11
The
Current Criterion
is the next parameter, item 47, and has
been preset to 90 dB in a range of 0 to 255 dB.
Step 3
Press the
d
key, item 47. Press
e
if you wish
to keep the 90 dB level, or press
m
, enter the
desired dB numerically and press
e
.
Damage to hearing normally
occurs with lengthy exposure to
sound at 90 dB and above. For this
reason the Criterion is generally
set at 90 dB.
The
Current Dose
is often used as a second Dose measure-
ment. The collected data is available on the printout.
The
Overall Dose
parameters have the same available settings
as the current settings and are accessed in the same way.
Step 4
To access items 48-50,
Overall Exchange Rate,
Overall Threshold, Overall Criterion
, press the
d
key.
Changes can be made in any dis-
play by pressing
m
, entering
desired values, and pressing
e
.
Full Dose Hours
, item 51, has a range of 0 to 99 hours but is
normally set to an 8 hour workday.
Step 5
To access Full Dose Hours press the
d
key.
The overall criterion level set in
item 50 and the dose hours set in
item 51 determine what is 100%
dose.
Parameters 52-54 are a second set used to calculate overall
dose from the overall data. Data already in memory is recalcu-
lated with new parameters using LDL (log Data Logic).
OSHA criterion is 90 dB, Thresh-
old is 80 dB, Exchange Rate is 5
dB, and the Full Dose hours (Cri-
terion Time) is 8 dB.
Step 6
To look at DOSE, press
E
.
Step 7
To look at Projected Dose, press
r
to the PROJ-b
screen.
This step will not work while in the
SETUP mode.
Step 8
If you wish to alter the LDL Exchange, Threshold or
Criterion settings, press
m
, enter the desired val-
ues, and press
e
.
Step 9
To look at LDL, press
U
and
E
.
This step will not work while in the
SETUP mode either.
