KANOMAX 3443 Digital Dust Monitor - Manual (Page 38)

3. Display Description and operation Procedure
32
H) TWA MODE
If you select TWA on the menu screen, the screen shown on the left will
be displayed.
You can configure TWA measurement setting and alarm setting.
TWA TIME (m): Measurement time setting (1 min ~ 48 hrs, settable by minutes)
TWA VALUE: Time-weighted average (0.001 ~ 10.000, STEL>TWA)
STEL VALUE: Short-term exposure limit (0.001 ~ 10.000, C>STEL>TWA)
C VALUE: Upper limit tolerance (0.001 ~ 10.000, C>STEL)
ALARM SET: Alarm ON/OFF setting
SAVE INFO: Save settings
Use [▲][▼] keys to move the cursor and press [SET] key to set it.
Press [MENU] key to go back to the UTILITY screen.
If an error is detected in the settings for TWA VALUE, STEL VALUE, C VALUE, [
ERROR! ] will be
indicated on the lower right of the screen for two seconds.
<Time-weighted average (TWA)>
Input Range: The short term exposure limit (STEL) or less in the range of [0.001-10.000] mg/m3
Time-weighted average (TWA) is the time-weighted average concentration for the regular working hours of
8 hours a day and 40 hours a week. When the average concentration (mg/m3) from the beginning to the
ending of the TWA mode measurement exceeds this set value, an alarm will be activated.
The TWA measurement value is displayed in real time.
If the measurement time is less than 8 hours, the time length till the end of the measurement is subject to this
measurement.
<Short term exposure limit (STEL)>
Input Range: Between the time-weighted average (TWA) and the upper limit tolerance (C) in the range of
[0.001-10.000] mg/m3
If the latest moving average concentration (mg/m3) for 15 minutes exceeds this setting value, an alarm will
be activated.
The short term exposure limit (STEL) is displayed in real time.
The alarm will also be activated if the concentration exceeds the time-weighted average (TWA) 5 times or
more within 8 hours or the concentration exceeds TWA twice or more within 60 minutes.
If the measurement time is less than 8 hours, the time length till the end of the measurement is subject to this
measurement.
<Upper limit tolerance (C)>
Input Range: The short-term exposure limit (STEL) or less in [0.001-10.000]mg/m3
If the instantaneous concentration (one sampling) (mg/m3) exceeds this set value, an alarm will be indicated.
The upper limit tolerance (C) is displayed in real time.