this publication may be reproduced, transmitted, transcribed, stored in a retrieval
system, or translated into any other language in any form by any means without the
express written permission of Met One Instruments, Inc.
Technical Support
Should you require support, please consult your printed documentation to resolve your
problem. If you are still experiencing difficulty, you may contact a Technical Service
representative during normal business hours—7:30 a.m. to 4:00 p.m. Pacific Standard
Time, Monday through Friday.
Met One Instruments, Inc.
1600 Washington Boulevard
Grants Pass, OR 97526
NOTICE
CAUTION—Use of controls or adjustments or performance of
procedures other than those specified herein may result in
hazardous radiation exposure.
WARNING—This product, when properly installed and operated, is
considered a Class I laser product. Class I products are not
considered to be hazardous.
There are no user serviceable parts located inside the cover of this device.
Do not attempt to remove the cover of this product. Failure to comply with this
instruction could cause accidental exposure to laser radiation.
Met One Instruments,
Inc.
1600 Washington Blvd
Grants Pass, Oregon
97526 U.S.A.
The AEROCET 831 is a small, lightweight, battery operated, handheld mass profiler.
This instrument simultaneously monitors PM1, PM2.5, PM4 and PM10 levels. The
multifunction rotary dial provides simple and efficient operation. The internal battery
pack provides 8 hours of continuous operation. The AEROCET 831 stores up to 2,500
sample events, which can be viewed on the display or exported to a computer via the
USB port.
1.1. About the Measurement
The AEROCET 831 counts and sizes particles in 7 different size ranges then uses a
proprietary algorithm to convert count data to mass measurements (µg/m3).
Fundamentally, the AEROCET 831 calculates a volume for each detected particle then
assigns a standard density for the conversion.
The standard density value is augmented by the K-Factor setting to improve
measurement accuracy. The AEROCET 831 provides a separate K-Factor setting for
each measurement range (PM1, PM2.5, PM4, PM10 and TSP). These K-Factors can
be modified with Comet software.
K-Factor values should be empirically derived via comparison with a reference unit. If a
reference unit is unavailable, the recommended K-Factor setting is 3.0.
1.2. Technical Service
This manual is structured by customer feedback to provide the required information for
setup, operation, testing, maintaining, and troubleshooting your unit. Should you still
require support after consulting your printed documentation, we encourage you to
contact one of our expert Technical Service representatives during normal business
hours of 7:00 a.m. to 4:00 p.m. Pacific Standard Time, Monday through Friday. In
addition, technical information and service bulletins are often posted on our website.
Please contact us and obtain a Return Authorization (RA) number before sending any
equipment back to the factory. This allows us to track and schedule service work and to
expedite customer service. Please have your instrument serial number available when
contacting the manufacturer.
AEROCET 831 Manual Rev A Page 3
2. Setup
ATTENTION:
The USB drivers on the included Comet CD must be installed before connecting the
AEROCET 831 USB port to your computer. If the supplied drivers are not installed
first, Windows may install generic drivers that are not compatible with this product.
Note:
For proper communication, set the
virtual COM port baud rate to 9600
32 Bit Operating Systems should
install the 32 bit USB drivers.
64 Bit Operating Systems should
install the 64 bit USB drivers.
The following sections cover unpacking, layout and performing a test run to verify
operation.
2.1. Unpacking
When unpacking a new AEROCET 831, verify that the contents are undamaged. Any
damages incurred to the equipment during shipping are the responsibility of the carrier.
If any damage to the shipment is noticed before unpacking, a claim must be filed with the commercial carrier immediately. You should follow any special unpacking
instructions provided by the carrier as you then carefully remove all items from the
containers and inspect each component. It is recommended to document and
photograph all damaged packages and items before, during, and after unpacking them.
Contact Met One Instruments (see section 1.2 of this manual) to arrange for any
replacement items needed.
Standard items (included) are shown in
Figure 1. Optional accessories are shown in Figure 2.
To install USB drivers:
Insert the Comet CD. The install program should run automatically and display the
screen below. If an AutoPlay pop-up window appears, select “Run AutoRun.exe”. Finally, select “USB Drivers” to start the install process.
AEROCET 831 Manual Rev A Page 4
AEROCET 831 Optional Accessories
AEROCET 831 Standard Accessories
AEROCET 831
PN AEROCET-831
Battery Charger
PN 390031
USB Cable
PN 500787
831 Manual
PN 831-9800
Calibration
Certificate
PN 831-9600
Comet Software
CD
PN 80248
Carrying Case
MOI P/N: 8517
Boot
MOI P/N: 80450
Zero Filter Kit
MOI P/N: 80846
Flow Meter Kit
MOI P/N: 80530
Power Cord
PN 400113
AEROCET 831 Manual Rev A Page 5
Figure 1 – Standard Accessories
Figure 2 – Optional Accessories
2.2. AEROCET 831 Layout
Component
Description
Display
2X16 character LCD display
Keyboard
2 key membrane keypad
Rotary dial
Multifunction dial (rotate and press)
Charger Jack
Input jack for external battery charger.
Flow Adjust
Adjusts the sample flow rate
Inlet Nozzle
Sample nozzle
USB Port
USB communication port
USB Port
Display
Charger Jack
Inlet Nozzle
Keyboard
Rotary Dial
Flow Adjust
The following figure shows the layout of the AEROCET 831 and provides a description
of the components.
Figure 3 – AEROCET 831 Layout
2.3. Initial Operation
Before operating the AEROCET 831 for the first time, it is recommended that the unit
be fully charged. Information regarding battery charging is found in Section 6.1.
Complete the following steps to verify proper operation.
1. Press the Power key for 0.5 seconds or more to turn on the power.
2. Observe the Startup screen for 3 seconds then the Sample screen (Section 3.5)
3. Press Start / Stop key. The AEROCET 831 will sample for one minute and stop.
4. Observe the mass values on the display
5. Rotate the Select dial to view additional PM ranges.
6. The unit is ready for use
AEROCET 831 Manual Rev A Page 6
3. Operation
AEROCET 831
WWW.METONE.COM
PM10 112.7 µg
██████████
Control
Description
Power Key
Power the unit on/off. For power on, press for 0.5 seconds or more.
Start/Stop Key
Sample Screen
START / STOP a sample event
Settings Menu
Return to Sample screen
Edit Settings
Cancel edit mode and return to the Settings Menu
Select Dial
Rotate the dial to scroll through selections or change values. Press the
dial to select item or value.
Selectable (rotate dial)
The following sections cover the basic operation of AEROCET 831.
3.1. User Interface
The AEROCET 831 user interface is composed of a rotary dial, 2 button keypad and a
LCD display. The keypad and rotary dial are described in the following table.
3.2. Power On/Off
Press and hold the Power key momentarily to power on the unit. Similarly, press and
hold the Power key momentarily to power off the unit. During power on, the AEROCET
831 will display the Startup Screen (Figure 4) for approximately 3 seconds then display
the Sample Screen.
Figure 4 – Startup Screen
Note: The AEROCET 831 will power down after 5 minutes to preserve battery power
providing the unit is stopped and there is no keyboard activity or USB communications.
3.3. Sample Modes
The AEROCET 831 has two sample modes: Manual and Continuous (Section 4.2.4).
Manual mode configures the unit for single sample events. Continuous mode
configures the unit for nonstop sampling.
3.4. Start/Stop a Sample
Press the START/STOP key to start a measurement. The AEROCET 831 will display
the progress bar below (Figure 5). In Manual mode, the AEROCET 831 will sample for
one minute and stop. In Continuous mode, the AEROCET 831 will run consecutive oneminute sample events until the operator presses the START / STOP key or the battery
is depleted. Use the select dial to select the PM range you want to display on the top of
the screen.
Figure 5 – Sampling Screen
AEROCET 831 Manual Rev A Page 7
3.5. Sample Screen
PM2.5 50.3 µg
LOW BATTERY!
PM2.5 50.3 µg
PM10 112.7 µg
Favorite range
Selectable (rotate dial)
The Sample Screen displays mass measurement results. The first line displays the
Favorite range (default = PM2.5). Select a Favorite range in the Settings Menu (Section
4.2.5) and the AEROCET 831 will pin the Favorite range to the top display line. The
second line scrolls (rotary dial) through the remaining ranges and battery capacity. The
Sample Screen is shown in Figure 6 below.
Figure 6 – Sample Screen
3.5.1. Warnings / Errors
Status messages are displayed on the second line of the Sample Screen. When this
occurs, simply rotate the dial to view any PM range on the top line.
A low battery warning indicates there is approximately 15 minutes of operation before
the AEROCET 831 stops sampling. A low battery condition is shown in Figure 7 below.
Figure 7 – Low Battery
The AEROCET 831 will display “Sensor Noise” or “Sensor Error” if it detects a problem
in the particle sensor. If you observe one of these messages, contact the service center
(see section 1.2).
4. Settings Menu
Use the Settings Menu to view or change settings. The Settings Menu is shown in
Table 1 below.
4.1. To View Settings
Press the Select dial to navigate to the Settings Menu. Rotate the Select dial to scroll
through the settings in Table 1. To return to the Sample screen press Start/Stop or wait
a few seconds and the unit will return automatically.
4.2. To Edit Settings
Press the Select dial to navigate to the Settings Menu. Rotate the Select dial to scroll to
the desired setting then press the Select dial to edit the Setting. A blinking cursor will
indicate edit mode. To cancel edit mode and return to the Settings Menu, press
Start/Stop.
AEROCET 831 Manual Rev A Page 8
Function
Description
LOCATION
Assign a unique number to a location or area. Range = 1 - 999
HISTORY
Display previous samples. See Section 4.2.2
FREE
MEMORY
Display the percent of available memory space. When Free
Memory = 0%, the oldest data will be overwritten with new data.
MODE
Manual mode for single sample events.
Continuous mode for nonstop sampling.
FAVORITE
Pin favorite PM range to the top display line.
SENSITIVITY
High (default): Improved sensitivity for normal operation.
Recommended use for indoors and low concentrations.
Low: Improved accuracy for higher concentrations. Recommended
use for outdoors and higher concentrations.
TIME
Display / set time. Time format is HH:MM:SS
(HH = Hours, MM = Minutes, SS = Seconds).
DATE
Display / set date. Date format is DD/MMM/YYY
(DD = Day, MMM = Month, YYYY = Year)
ABOUT
Display model number and firmware version
Press to Change
LOCATION 001
View screen. Press Select to enter Edit mode.
Rotate and Press
LOCATION 001
Blinking cursor indicates Edit mode. Rotate dial to scroll value.
Press dial to select next digit. Repeat action until last digit.
Rotate and Press
LOCATION 001
Rotate dial to scroll value. Press dial to exit Edit Mode and
return to view screen.
Press to View
HISTORY
Press Select to view history.
30/MAR/2011 L001
10:30:45 #1000
AEROCET 831 will display the last record (Date, Time,
Location, and Record Number). Rotate dial to scroll through
records. Press dial to view record.
Rotate dial to scroll through record data. Press Start/Stop to
return to previous screen.
4.2.3. Free Memory
Press to Change
FREE MEMORY 80%
View available memory. Press Select to enter edit mode.
Press and Hold
to Clear Memory
Press and hold Select dial for 3 seconds to clear memory and
return to view screen. Return to view screen if no action for 3
seconds.
Press to Change
MODE MANUAL
View screen. Press Select to enter Edit mode.
Rotate and Press
MODE MANUAL
Blinking cursor indicates Edit mode. Rotate dial to toggle value.
Press dial to select value and return to view screen.
Press to Change
FAVORITE PM2.5
View screen. Press Select to enter Edit mode.
Rotate and Press
FAVORITE PM2.5
Blinking cursor indicates Edit mode. Rotate dial to scroll
ranges. Press dial to select range and return to view screen.
Press to Change
SENSITIVITY HIGH
View screen. Press Select to enter Edit mode.
Rotate and Press
SENSITIVITY HIGH
Blinking cursor indicates Edit mode. Rotate dial to toggle value.
Press dial to select value and return to view screen.
Press to Change
TIME 10:30:45
View time. Press Select to enter edit mode.
Rotate and Press
TIME 10:30:45
Blinking cursor indicates Edit mode. Rotate dial to scroll values.
Press dial to select next digit. Repeat action until last digit.
Rotate and Press
TIME 10:30:45
Last digit. Rotate dial to scroll values. Press dial to exit Edit
mode and return to view screen.
4.2.4. Mode
4.2.5. Favorite
4.2.6. Sensitivity
4.2.7. Time
AEROCET 831 Manual Rev A Page 10
4.2.8. Date
Press to Change
DATE 30/MAR/2011
View date. Press Select to enter edit mode.
Rotate and Press
DATE 30/MAR/2011
Blinking cursor indicates Edit mode. Rotate dial to scroll values.
Press dial to select next digit. Repeat action until last digit.
Rotate and Press
DATE 30/MAR/2011
Rotate dial to scroll values. Press dial to exit Edit mode and
return to view screen.
AEROCET 831
80865-1 V2.0.0
View model number and firmware version.
Note:
For proper communication, set the
virtual COM port baud rate to 38400
32 Bit Operating Systems should
install the 32 bit USB drivers.
64 Bit Operating Systems should
install the 64 bit USB drivers.
4.2.9. About
5. Serial Communications
Serial communications, firmware field upgrades and real time output are provided via
the USB port located on the side of the unit.
5.1. Connection
ATTENTION:
The USB drivers on the included Comet CD must be installed before connecting the
AEROCET 831 USB port to your computer. If the supplied drivers are not installed first,
Windows may install generic drivers that are not compatible with this product.
To install USB drivers:
Insert the Comet CD. The install program should run automatically and display the
screen below. If an AutoPlay pop-up window appears, select “Run AutoRun.exe”.
Select “USB Drivers” to start the install process. Follow the on-screen prompts to
complete the installation process. You may be prompted to re-boot your computer
when the driver installation is complete.
AEROCET 831 Manual Rev A Page 11
5.2. Commands
Serial Settings
Value
Port Name
The COM port connected to the device. (ie. COM1)
Baud Rate
38400
Data Bits
8
Parity
None
Stop Bits
1
Command
Type
Description
?,H
Help
View the help menu
1
Settings
View the settings
2
All data
Returns all available records.
3
New data
Returns all records since last ‘2’, ‘3’or ‘4’ command.
4
Last data
Returns the last record or last n records (n = <Value>)
D
Date
Change date. Date is format is MM/DD/YY
T
Time
Change time. Time format is HH:MM:SS
C
Clear data
Displays a prompt for clearing the stored unit data.
S
Start
Start a sample
E
End
Ends a sample (abort the sample, no data record)
ID
Location
View / change the location number. Range 1-999.
OP
Op Status
Replies OP x, where x is “S” Stopped or “R” Running
RV
Revision
View Software Revision
SM
Mode
0 = Manual, 1 = Continuous
SK
K-Factor
View / change K-Factors
x = 1 - 5 (PM1, PM2.5, PM4, PM10, TSP)
y = K-Factor value
Range = 0.10 to 20.0
Format: SKx yy
Examples:
SK1 2.0 changes PM1 K factor to 2.0
SK2 1.9 changes PM2.5 K factor to 1.9
The AEROCET 831 provides serial commands for accessing stored data and settings.
All commands are terminated by a carriage return. Also, these commands are not case
sensitive. The following tables list the available commands. These commands are
available via USB. The settings (baud rate, parity and stop bits) must match the
computer setting.
Table 2, Serial Settings
Table 3, Serial Commands
AEROCET 831 Manual Rev A Page 12
5.3. Real Time Output
Code
Error/Alarm Type
000
Normal/No Alarm
016
Low Battery
032
Sensor Error
064
Sensor Noise
112
Low Battery, Sensor Error, and Sensor Noise
128
File System Error – Bad Memory
WARNING:
There are no user serviceable components inside this instrument. The covers
on this instrument should not be removed or opened for servicing, calibration
or any other purpose except by a factory-authorized person. To do so may
result in exposure to invisible laser radiation that can cause eye injury.
The AEROCET 831 outputs real time data at the end of each sample. The output
format is a comma separated values (CSV). The following sections show the format.
5.4. Comma Separated Value (CSV)
A CSV header is included for multiple record transfers like Display All Data (2) or
Display New Data (3).
To charge the battery, connect the battery charger module AC power cord to an AC
power outlet and the battery charger DC plug to the socket on the side of the
AEROCET 831. The universal battery charger will work with power line voltages of 100
to 240 volts, at 50/60 Hz. The battery charger LED indicator will be Red when charging
and Green when fully charged. A discharged battery pack will take approximately 2.5
hours to fully charge.
When fully charged, the battery will power the AEROCET 831 for approximately 8 hours
of continuous sampling or 24 hours of intermittent sampling. For extended operation,
operate the unit with the battery charger attached. Also, charge the battery before
storing the AEROCET 831. Storing a discharged battery will degrade its performance.
AEROCET 831 Manual Rev A Page 13
6.2. Service Schedule
Item To Service
Frequency
Done By
Flow rate test
Monthly
Customer
Zero test
Optional
Customer or Factory Service
Calibrate Sensor
Yearly
Factory service only
Caution:
The provided battery charger is designed to work safely with this device. Do
not attempt to connect any other charger or adapter to this device. Doing so
may result in equipment damage.
Table 2 shows the recommended service schedule for the AEROCET 831.
Table 2, Service Schedule
6.2.1. Flow Rate Test
The sample flow rate is factory set to 0.1 CFM (2.83 LPM). Continued use and ambient
temperature/pressure variations may cause minor changes in flow which can reduce
measurement accuracy. A flow calibration kit is available separately that includes
everything needed to test/adjust the flow rate. To test the flow rate:
Remove the inlet screen holder
Connect the flow meter with inlet adapter (PN 80530) to the instrument inlet
Start a sample
Observe the flow meter reading after approximately 30 seconds
The flow rate should be 0.1 CFM (2.83 LPM) 5%
If the flow is not within this tolerance, it can be adjusted using a trim pot located in an
access hole in the side of the unit. Turn the adjustment pot clockwise to increase the
flow and counter-clockwise to decrease the flow.
6.2.2. Zero Count Test
The AEROCET 831 automatically monitors system noise and displays a System Noise
warning when the noise level is high (see Section 3.5.1). This diagnostic reduces the
necessity for an inlet filter zero count test. However, a zero count kit (PN 80846) can be
purchased separately if desired.
6.2.3. Annual Calibration
The AEROCET 831 should be sent back to Met One Instruments yearly for calibration
and inspection. Particle counter calibration requires specialized equipment and
training. The Met One Instruments calibration facility uses industry accepted methods
such as ISO and JIS.
In addition to calibration, the annual calibration includes the following preventative
maintenance items to reduce unexpected failures:
Inspect the exhaust filter
AEROCET 831 Manual Rev A Page 14
Inspect and clean the optical sensor
Symptom
Possible Cause
Correction
Low battery message
Low battery
Charge battery 2.5 hrs
Sensor Noise
Possible contamination
Contact service center
Sensor Error
Sensor failure
Send to service center
Does not turn on, no
display
1. Dead battery
2. Defective Battery
1. Charge battery 2.5 hrs
2. Send to service center
Display turns on but pump
does not
1. Low Battery
2. Defective pump
1. Charge battery 2.5 hrs
2. Send to service center
Suspect measurement
values
1. Flow rate off
2. Inlet screen clogged
1. Check flow rate
2. Check inlet screen
Battery pack does not hold
a charge
1. Defective battery pack
2. Defective charger
module
1. Send to service center
2. Contact service center
Inspect the pump/tubing
Cycle and test the battery
6.3. Flash Upgrade
Firmware can be field upgraded via the USB port. Binary files and the flash program
must be provided by Met One Instruments.
7. Troubleshooting
The following table covers some common failure symptoms, causes and solutions.