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6-3 Determining SPAN and ZERO Values by
Calibration
The SPAN and ZERO values are determined using the following formulas.
SPAN =
Reference Measurement Value
ZERO = Reference Measurement Value - Display Value
Display Value
OR
To calibrate the values based on a constantly changing value, such as temperature or
atmospheric pressure, it is easier to correct accuracy by changing the ZERO value.
6-4 Accumulated and Average Flowrate Display
During flowrate measurements, average flowrate and accumulated flowrate can be
displayed for a given time interval (max. 9 hours 59 minutes).
This feature is especially useful for calculating flowrate values during manual calibration
of low volume pumps and PM2.5 samplers.
(1) Press the [Enter] key during a measurement (displays the [TIMER] indicator).
(2) Press the [ENTER] key again (the indicator disappears).
(3) With the manual setting, the accumulated flowrate and average flowrate are displayed
for the period between the first and second time the [ENTER] key was pressed.
With the timer setting, press the [ENTER] key to activate the timer. The accumulated
flowrate and average flowrate will be displayed when the set time has elapsed or the
[ENTER] key is pressed once again.
Note: While the accumulated flowrate is being measured, if the timer set time is
min. 1 hour, “Hours” and “Minutes” will be displayed. If it is less than 1 hour,
“Minutes” and “Seconds” will be displayed.
(4) Press the [ENTER] key to display the instantaneous flowrate again.
*1
The display can be switched and checked even during
measurements.
Calibrate by changing either the SPAN or ZERO value. Do not attempt to change
both values.
Instantaneous value
Ending point
(
→
resulting average)
Starting point
(Display switching
*1
)
