072-0300
Alphasense User Manual
OPC-N2 Optical Particle Counter
Issue 5
Alphasense Ltd Page 9 of 34
December 2015
Sensor Technology House, 300 Avenue West, Skyline 120, Great Notley. Essex.CM77 7AA. UK
Tel: +44 (0) 1376 556700 - Fax: +44 (0) 1376 335899
Email: [email protected] - Web: www.alphasense.com
•
Device information
(Right hand side text window): This shows hardware serial number and
firmware versions currently installed on the OPC-N2.
•
Start sampling
: Starts data collection with the fan and laser running continuously. The
button will then show ‘Stop sampling’ to allow termination of the sampling process.
•
Repeat interval ms
: Sets the duration (in milliseconds) over which a particle size histogram
is acquired. The default is 1,000 ms. We recommend a maximum of 10,000 ms to avoid the
risk of an individual size bin becoming full (65,536 counts). Longer intervals can be set in
very clean environments, but the unit will reset if no communication is received for 65s.
•
Y max
: This sets the maximum y-axis value of the histogram screen display.
Note
: If the
displayed data reaches the top of the display, enter a larger Y max value.
•
Histogram y-axis
‘Counts/ s’:
This displays the recorded counts per second in each size bin,
regardless of the setting of the ‘Repeat interval ms’. For example, if a 10,000 ms sampling
interval is set, the ‘Counts/ s’ figure will represent the average counts per second over that
period. This average figure is also recorded in the CSV file.
Histogram Counts/s vs Particle Size display mode
When the
Start sampling
button is pressed, the OPC-N2 will first ask if the data are to be saved.
Once answered, it will begin to display particle size histogram data and if selected, store data to a
file.
