Met One Instruments AEROCET 531S User manual

Met One Instruments, Inc
Corporate Sales & Service: 1600 NW Washington Blvd. Grants Pass, OR 97526
Tel [phone] Fax [phone]
www.metone.com [e-mail]
AEROCET 531S
MANUAL

AEROCET 531S Manual Rev H Page 2
Copyright Notice
AEROCET 531S Manual
© Copyright 2014 Met One Instruments, Inc. All Rights Reserved Worldwide. No part of
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
This manual is structured by customer feedback to provide the required information for
setup, operation, testing, maintaining, and troubleshooting your Aerocet 531S. 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 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.
Contact
Information:
Tel: + 541 471 7111
Fax: + 541 471 7115
Web: www.metone.com
Email: [e-mail]
Address:
Met One Instruments, Inc.
1600 NW Washington Blvd
Grants Pass, Oregon 97526
U.S.A.
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.

AEROCET 531S Manual Rev H Page 3
Table of Contents
1. Introduction........................................................................................................... 5
2. Setup...................................................................................................................... 5
2.1. Unpacking..................................................................................................................................5
2.2. Layout........................................................................................................................................8
2.3. Default Settings .........................................................................................................................9
2.4. Initial Operation .........................................................................................................................9
3. User Interface ........................................................................................................ 9
4. Operation............................................................................................................. 10
4.1. What’s New and Different........................................................................................................10
4.2. About the Measurement ..........................................................................................................10
4.3. Power Up.................................................................................................................................10
4.4. Operate Screen .......................................................................................................................11
4.4.1. Sampling ...........................................................................................................................12
4.4.2. Sample Status...................................................................................................................12
4.4.3. Sample History..................................................................................................................12
4.4.4. Warning / Error Messages ................................................................................................13
4.5. Sample Related Functions ......................................................................................................13
4.5.1. Starting/Stopping...............................................................................................................13
4.5.2. Measurement Type...........................................................................................................13
4.5.3. Sample Mode....................................................................................................................13
4.5.4. Hold Time..........................................................................................................................13
4.5.5. Real-Time Serial Report ...................................................................................................13
4.5.6. Sample Timing..................................................................................................................14
5. Menu Selections.................................................................................................. 14
5.1. Edit Menu Items.......................................................................................................................15
5.2. Sample Setup Screen..............................................................................................................15
5.2.1. Location Number...............................................................................................................15
5.2.2. Measure ............................................................................................................................15
5.2.3. Sample Mode....................................................................................................................16
5.2.4. Hold Time..........................................................................................................................16
5.3. Settings Screen .......................................................................................................................16
5.3.1. Volume..............................................................................................................................16
5.3.2. Temperature......................................................................................................................16
5.3.3. Sensitivity..........................................................................................................................16
5.4. Serial Screen...........................................................................................................................17
5.4.1. Report ...............................................................................................................................17
5.4.2. Baud Rate .........................................................................................................................17
5.4.3. Serial.................................................................................................................................17
5.5. Recall Data Screen..................................................................................................................18
5.6. Print Data Screen ....................................................................................................................18

AEROCET 531S Manual Rev H Page 4
5.7. Memory Screen .......................................................................................................................19
5.7.1. View Available Memory.....................................................................................................19
5.7.2. Clearing Memory...............................................................................................................19
5.8. Set Flow Screen ......................................................................................................................20
5.9. Set Clock Screen.....................................................................................................................20
5.10. Set Contrast Screen ................................................................................................................21
5.11. About Screen...........................................................................................................................21
6. Charging the Battery........................................................................................... 21
7. Serial Communications ...................................................................................... 22
7.1. Serial Interface ........................................................................................................................23
7.2. Commands ..............................................................................................................................24
7.3. Real Time Output ....................................................................................................................25
7.4. Comma Separated Value (CSV) .............................................................................................26
7.4.1. Counts Format ..................................................................................................................26
7.4.2. Mass Format.....................................................................................................................27
7.5. Printer Format..........................................................................................................................29
7.5.1. Counts Format ..................................................................................................................29
7.5.2. Mass Format.....................................................................................................................29
8. Maintenance ........................................................................................................ 29
8.1. Service Schedule.....................................................................................................................29
8.2. Zero Count Test.......................................................................................................................30
8.3. Flow Rate Test.........................................................................................................................30
8.4. Annual Calibration ...................................................................................................................30
8.5. Flash Upgrade.........................................................................................................................30
9. Troubleshooting.................................................................................................. 31
10. Specifications...................................................................................................... 32
11. Warranty / Service............................................................................................... 33

AEROCET 531S Manual Rev H Page 5
1. Introduction
The AEROCET 531S is a full–featured, battery operated, handheld particle counter or
mass monitor.
In count mode, the unit will measure particle counts at four fixed sizes (0.5 µm, 1.0 µm,
5.0 µm, and 10.0 µm) when set to low sensitivity and five fixed sizes (0.3 µm, 0.5 µm,
1.0 µm, 5.0 µm, and 10.0 µm) when set to high sensitivity (See Section 5.3.3 for more
detail).
In mass mode the unit will measure PM1, PM2.5, PM4, PM7, PM10 and TSP mass
concentration levels.
This instrument can store up to 6,000 sample events including data from the optional
ambient temperature (AT) / relative humidity (RH) probe (PN G3120). Sample history
events can be viewed on the LCD display, printed on the optional printer (PN G3115)
and download to a computer.
2. Setup
The following sections cover unpacking, layout and performing a test run to verify
operation.
2.1. Unpacking
Unpack and inspect the contents of the shipping container. Standard items (included)
are shown in Figure 1 –Standard Accessories. Optional accessories are shown in
Figure 2 –Optional Accessories. Contact the supplier if any items are missing. Any
damages incurred 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
the Technical Support section at the beginning of this manual) to arrange for any
replacement items needed.

AEROCET 531S Manual Rev H Page 6
ATTENTION:
The included USB drivers must be installed before connecting the AEROCET 531S
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”.
Finally, select “USB Drivers” to start the install process. You may be prompted to re-
boot your computer when the driver installation is complete.
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.

AEROCET 531S Manual Rev H Page 7
Figure 1 –Standard Accessories
Printer
PN G3115
Flow Meter
PN 9801
Serial Cable
PN 3228
T/RH Probe
PN G3120
Figure 2 –Optional Accessories
AEROCET 531S Standard Equipment
AEROCET 531S
PN AEROCET-531S
Battery Charger
PN 390031
Power Cord
PN 400113
Carrying Case
PN 8517
Calibration Certificate
AEROCET-531S-9600
ISO-Kinetic Probe
PN G3110
Zero Count Filter
PN G3111
USB Cable
PN 500787
Comet Software CD
PN 80248
Manual
AEROCET-531S-9800
PN
PN

AEROCET 531S Manual Rev H Page 8
2.2. Layout
The following figure shows the layout of the AEROCET 531S and provides a description
of each of the components.
Figure 3 –AEROCET 531S Layout
Component
Description
Power Switch
Switch that turns the AEROCET 531S on or off. Slide up (towards inlet
nozzle) to turn on and slide down to turn off.
Charging Jack
Input jack for the battery charger. This connection charges the internal
battery pack and provides continuous operating power for the unit.
USB Port
For USB serial communication
Serial Port
For serial communication (RS-232 or RS-485).
AT/RH Connector
Mating connector for the optional external ambient temperature (AT) and
relative humidity (RH) sensor. (PN G3120)
Inlet Nozzle
Ambient air inlet nozzle. Connect isokinetic probe to reduce turbulence
in the air sample.
Charging Jack
Inlet Nozzle
AT/RH Connector
USB Port
Serial Port
Power Switch

AEROCET 531S Manual Rev H Page 9
2.3. Default Settings
The AEROCET 531S comes with the user settings configured as follows.
Parameter
Value
Sample Location
1
Sample Type
Mass (µg/m3)
Sensitivity
High
Sample Mode
Manual
Sample Hold Time
0 seconds
Volume (concentration)
CF (particles / ft3)
Temperature Units
C
Baud Rate
9600
Serial Mode
RS-232
2.4. Initial Operation
Before operating the AEROCET 531S for the first time, it is recommended that the unit
be fully charged. Information regarding charging the battery is found in section 6 of this
manual.
Complete the following steps to verify proper operation.
1. Slide the power switch up to turn on the power.
2. Observe the Startup screen for 2 seconds then the Operate screen (Section 4.4)
3. Press START/STOP key. The AEROCET 531S will sample for 1 minute and stop.
4. Observe the PM levels on the display
5. Use the up / down arrows to view other PM levels
6. The unit is ready for use
3. User Interface
The AEROCET 531S user interface is composed of a 7 button keypad and a LCD
display. The following table describes keypad functionality. Note some keys have more
than one function.
Key
Description
Starts or stops a sample.
Starts the unit printing when in the PRINT DATA screen.
Recalls the selected data when in the RECALL DATA screen.
Loads the Menu screen when not in edit mode.
Loads the Operate screen when in the Menu screen.
Cancel edit mode and return the field to the original value.
Loads the screen associated with menu item.
Begins editing of the selected item.
Stops editing a field and saves the changed value.
Scroll sizes (Operate screen)
Navigates up/down when not editing (Menu).
Modifies field when editing.
Navigates right / left
Move through history buffer (Operate screen)
MENU
ESC
ENTER
STOP
START

AEROCET 531S Manual Rev H Page 10
4. Operation
The following sections cover the basic operation.
4.1. What’s New and Different
You should be aware of key differences between the AEROCET 531S and 531.
Description
531S
531
Comments
Sensitivity
High / Low
0.5 µm
0.3 µm = High, 0.5 µm = Low
Mass Concentration Units
µg/m3
mg/m3
Mass Concentration Precision
0.1 µg /m3
0.001 mg/m3
Higher precision
Sample Time
1-minute
2-minutes
Faster sample time
Hold Time Units
Seconds
Minutes
Shorter hold times
Contrast Adjust
Software
Mechanical
No tools required. See Section 5.10
Battery
Lithium-ion
NiMh
Warning: See Section 6
4.2. About the Measurement
The AEROCET 531S counts and sizes particles in 8 different size ranges then uses a
proprietary algorithm to convert count data to mass measurements (µg/m3).
Fundamentally, the AEROCET 531S 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 531S provides a separate K-Factor setting for
each measurement range (PM1, PM2.5, PM4, PM7, PM10, and TSP). These K-Factors
can be modified with Comet software or with the SK serial port command.
K-Factor values should be empirically derived via comparison with a reference unit. If a
reference unit is unavailable, the recommended (default) K-Factor setting is 3.0.
4.3. Power Up
AEROCET 531S power is controlled by a slide switch located on the right hand side of
the unit. Move the power switch to the on position (towards the top of the case) to power
up the unit.
The first screen shown on power up is the Startup screen (Figure 4). This screen
displays the product type and company website for 2 seconds before loading the
Operate Screen.
AEROCET 531S
WWW.METONE.COM
Figure 4 –Startup Screen

AEROCET 531S Manual Rev H Page 11
4.4. Operate Screen
The Operate screen can display the count or mass measurement. It is determined by
the MEASURE setting. The Operate screen displays the date and time, sample status,
current sample data and previous sample data. Figure 5 and Figure 6 shows the Mass
and Count screens.
When sampling in mass mode, the size selection represents the upper threshold of your
sample. For example, when you read the value for PM10 it contains all mass that is
size PM10 and lower. Conversely, when sampling in count mode, the size selections
represent the lower threshold of your sample. An example would be that the 1.0 µm
size contains all particulate that are 1.0 µm and larger.
22 JAN’13 17:56
PM1 1.1 µg
PM2.5 3.3 µg
PM4 4.6 µg
PM7 5.5 µg
PM10 6.7 µg
TSP 10.6 µg
AT 21 C
RH 45 %
LOCATION 001
Figure 5 –Mass Operate Screen with AT and RH
22 JAN’13 17:56
0.5u 24,600 TC
1.0u 2,516 TC
5.0u 44 TC
10 u 21 TC
AT 21 C
RH 45 %
LOCATION 001
Figure 6 –Count Operate Screen with AT and RH
The top line of the Operate screen is reserved for the normal header (date and time) or
status/alarm messages depending upon the machine status. The top line remains
stationary while the other 3 lines scroll to display the full list. AT and RH data will
precede the location number when the AT/RH probe is attached.
Ambient temperature (AT) can be displayed in units of Celsius (C) or Fahrenheit (F).

AEROCET 531S Manual Rev H Page 12
4.4.1. Sampling
The Operate screen displays current sample information when the unit is sampling (real
time data). Concentration values (µg/m3) are time dependent so these values may
fluctuate early in the sample; however, after several seconds the measurement will
stabilize. Figure 7 shows the Operate screen while sampling.
█ 58
PM1 1.0 µg
PM2.5 2.4 µg
PM4 3.5 µg
Figure 7 –Operate Screen Sampling
4.4.2. Sample Status
The top line of the Operate screen displays the status of the AEROCET 531S while the
unit is sampling. The following table shows the various status messages:
Status
Description
STARTING...
AEROCET 531S is starting the sample and is waiting for the
count system to initialize.
HOLDING...
AEROCET 531S is in auto mode and is waiting for the hold time
to finish.
STOPPING...
AEROCET 531S is stopping the sample and is waiting for the
count system to stop.
█ █ █ █ █ █ 10
AEROCET 531S is sampling. The progress bar moves from left
to right as the sample progresses. The time remaining is
displayed to the far right.
4.4.3. Sample History
Sample history (previous data) can be viewed on the Operate screen when the unit is
stopped (not sampling). To view sample history, press the ENTER key or ◄ from the
Operate screen. The unit will display the last sample event (newest record) and display
“” in the upper right corner of the display (see Figure 8) to indicate history data. Press
◄ or ► to move through sample history one record at a time (◄displays older events,
►displays newer events). Press the ENTER key at any time to return to the Operate
screen. Press START at any time to start a new sample.
03 DEC’12 11:23
PM1 0.0 µg
PM2.5 0.0 µg
PM4 0.0 µg
Figure 8 –History Screen

AEROCET 531S Manual Rev H Page 13
4.4.4. Warning / Error Messages
The AEROCET 531S displays warning/error messages on the top line of the Operate
screen. These messages alternate with the normal date/time header. The following
table lists the warning/error messages:
Display Message
Description
LOW BATTERY!
Low battery warning. Less than 15 minutes of normal operation remaining.
SENSOR ERROR!
Particle sensor error.
4.5. Sample Related Functions
The following sub-sections cover sample related functions.
4.5.1. Starting/Stopping
To start or stop a sample, press the START/STOP key. A sample event can be manually
started or stopped from either the Operate screen or the menu.
4.5.2. Measurement Type
The measurement type determines if the instrument reports mass (µg/m3) or particle
concentration (particles/volume). Measurement type is discussed in section 5.2.
4.5.3. Sample Mode
The sample mode controls single sample or continuous sampling. The MANUAL setting
configures the unit for a single sample. The AUTO setting configures the unit for
continuous sampling. Sample modes are discussed in section 5.2.
4.5.4. Hold Time
The hold time is used when the sample mode is set to auto (continuous sample). The
hold time represents the time from the completion of the last sample to the start of the
next sample. The hold time is user settable from 0 –999 seconds and is discussed in
section 5.2.
4.5.5. Real-Time Serial Report
AEROCET 531S provides real-time report out the serial port at the end of each sample.
The format of the report is controlled by the REPORT setting (Section 5.4). Section 7.3
covers the real-time output format.

AEROCET 531S Manual Rev H Page 14
4.5.6. Sample Timing
The following figures depict the sample timing sequence for both manual and auto
sampling modes. The sample time is fixed at 60 seconds. Figure 9 shows the timing for
manual sample mode. Figure 10 shows the timing for auto sample mode.
Figure 9 –Manual Mode Sample
Figure 10 –Auto Mode Sample
5. Menu Selections
The menu is accessible by pressing the MENU key on the Operate screen. The table
below shows the menu items. Press ▲ or ▼ to navigate to a menu item then press
ENTER to display a screen where you can view or change item setting(s).
Menu Item
Description
Press ENTER to
navigate to…
SAMPLE SETUP
View / change location number, auto / manual
mode, sample type and hold time.
Sample Setup screen
SETTINGS
View / change volume, ºC / ºF and Sensitivity
Settings screen
SERIAL
View / change report type, baud rate and
serial output mode.
Serial screen
RECALL DATA
Recall sample history based on time.
Recall Data screen
PRINT DATA
Print stored data based on a time range.
Print Data screen
MEMORY
View memory usage and clear memory.
Memory screen
SET FLOW
Adjust the sample flow rate
Flow screen
SET CLOCK
Set the date and time.
Set Clock screen
SET CONTRAST
Adjust the display contrast.
Set Contrast screen
ABOUT
Display firmware version and serial number.
About screen
Start
Time Sample Time Stop
Time
Start
Time Sample Time Hold Time Sample Time Stop Time

AEROCET 531S Manual Rev H Page 15
5.1. Edit Menu Items
To change settings, press MENU to display the main menu, press ▲ or ▼ to navigate to
the desired item and press ENTER to display the item view/edit screen.
To edit pick list items (e.g. SAMPLE SETUP MODE: AUTO or MANUAL), press ▲ or ▼ to
navigate to the item. Press ENTER to select the item. Press ▲ or ▼ to change the
setting. Press ENTER to save the setting or ESC to cancel and return to the main value.
To edit numeric values (e.g. LOCATION), press ▲ or ▼ to navigate to the item. Press
ENTER to select the item. Press ▲ or ▼ to increment or decrement a value. Press ◄ or
► to select the next digit. Press ENTER to save the value or ESC to cancel and return to
the main value.
5.2. Sample Setup Screen
Figure 11 shows the SAMPLE SETUP Screen. The 4 parameters are covered in the
following sections.
LOCATION: 001
MEASURE: COUNTS
MODE: MANUAL
HOLD: 000
Figure 11 –SAMPLE SETUP Screen
5.2.1. Location Number
The LOCATION number is used to assign a unique number to a location or area. This
important field is included in sample data records (display, printer and csv output).
5.2.2. Measure
The MEASURE is either MASS or COUNTSconcentration.
Selection
Description
MASS
When MASS is selected the unit will report PM levels
PM1, PM2.5, PM4, PM7, PM10 and TSP in µg/m3.
COUNTS
When COUNTSis selected the unit will report fixed
particles sizes.
0.5 µm, 1.0 µm, 5.0 µm, and 10.0 µm when using
low sensitivity
0.3 µm, 0.5 µm, 1.0 µm, 5.0 µm, and 10.0 µm
when using high sensitivity.

AEROCET 531S Manual Rev H Page 16
5.2.3. Sample Mode
The sample MODE controls single sample or continuous sampling as illustrated below.
Selection
Description
MANUAL
The MANUAL setting configures the unit for a single sample.
AUTO
The AUTO setting configures the unit for continuous sampling.
5.2.4. Hold Time
The HOLD time is the time between samples when sampling in AUTO mode (continuous).
The HOLD time is user settable from 0 –999 seconds. The pump will remain on during
the hold period if the HOLD time is 60 seconds or less. The pump will stop after each
sample, and start a few seconds before the next sample, if the HOLD time is greater
than 60 seconds. HOLD times greater than 60 seconds will increase pump life.
5.3. Settings Screen
Figure 12 shows the SETTINGS screen.
VOLUME CF
TEMPERATURE C
SENSITIVITY LOW
Figure 12 –SETTINGS Screen
5.3.1. Volume
The AEROCET 531S supports total counts (TC), particles per liter (/L), particles per
cubic foot (CF), and particles per cubic meter (M3). Particle count information updates
while the unit is sampling. Concentration values (/L, CF, M3) are time dependent so
these values may fluctuate early in the sample; however, after several seconds the
measurement will stabilize.
5.3.2. Temperature
The AEROCET 531S displays ambient temperature (AT) in Celsius (C) or Fahrenheit
(F).
5.3.3. Sensitivity
Select HIGH (0.3 µm) or LOW (0.5 µm) sensitivity. The default setting is HIGH. Use this
setting for normal operation. Use the Low setting for high concentrations (for example,
above 100 µg/m3) or when comparing measurements with older AEROCETS.

AEROCET 531S Manual Rev H Page 17
5.4. Serial Screen
Figure 12 shows the SERIAL screen.
REPORT: NONE
BAUD: 38400
SERIAL: RS-232
Figure 13 –SERIAL Screen
5.4.1. Report
The REPORT setting determines the behavior of the AEROCET 531S serial output and
report format. The settings are NONE, CSV or PRINTER. The following table lists the
REPORT settings and describes their meanings. See section 7 for report examples.
Selection
Description
NONE
No report is sent to the serial port at the end of the sample
event. Reports initiated from the user interface or a serial
command will be in a CSV style report.
CSV
A CVS style report is sent to the serial port at the end of the
sample event or when initiated from the user interface or a
serial command.
PRINTER
A printer style report is sent to the serial port at the end of the
sample event or when initiated from the user interface.
Reports initiated by a serial command will be in a CSV style
report.
5.4.2. Baud Rate
Use the BAUD rate selection to set the serial communications baud rate. AEROCET
531S communicates at baud rates from 300 –38400.
5.4.3. Serial
The SERIAL setting controls the behavior of the AEROCET 531S serial output
hardware. The modes are RS-232 or RS-485. The following table lists the SERIAL
settings and describes their meanings.
Serial Setting
Description
RS-232
Set to RS-232 when communicating with RS-232/USB
hardware.
RS-485
Set to RS-485 when communicating with RS-485 hardware.

AEROCET 531S Manual Rev H Page 18
5.5. Recall Data Screen
Stored sample events can be viewed from the Operate screen but this requires
navigating one record at a time to reach a desired record. The RECALL DATA screen
provides a way to quickly navigate to a record based on time. Figure 14 shows the
RECALL DATA screen.
RECALL DATA
01 JAN’00 00:00
Figure 14 –Recall Data Screen
To recall data, enter the desired date/time string and select the START/STOP button.
The unit will recall the data from the date/time entered (if an exact match is found) or the
next most recent data available. The screen shown when the data is recalled is the
Operate screen. The unit will display “” on the upper right corner of the display to
indicate history data.
5.6. Print Data Screen
Stored sample events can be printed through the serial port within a user selected
range. To print selected data, select PRINT DATA from the menu. Figure 15 shows the
PRINT DATA screen.
MEASURE: COUNTS
LOCATION: 001
01 JAN’00 00:00
18 AUG’06 13:23
Figure 15 –Print Data Screen
Edit the location and time range to select which sample events to print. The following
table describes settings.
Setting
Description
MEASURE
Print MASS or COUNTSdata type events.
LOCATION
The location ID of the sample events to print. Setting
location to 000 prints all locations. Settable from 0 –999.
01 JAN’00 00:00
The date/time to begin printing sample events from.
18 AUG’06 13:23
The date/time to end printing samples.

AEROCET 531S Manual Rev H Page 19
After the print settings have been selected, the PRINTING STATUS screen is displayed.
Figure 16 shows the PRINTING STATUS screen as it would look when finished.
PRINTING STATUS
SCANNING...15
PRINTING...10
FINISHED!
Figure 16 –Printing Status Screen
Pressing the ESC button cancels the data printing and loads the menu. The format of
the print is dependent upon the SERIAL setting (Section 5.4).
5.7. Memory Screen
The AEROCET 531S memory is composed of a single file which contains the data from
sample events. Every time a sample is completed, the AEROCET 531S stores that
data into the memory. The AEROCET 531S memory is circular, meaning when the
memory is full, the unit will start overwriting the oldest saved samples with new
samples. AEROCET 531S provides the user the ability to view the memory usage as
well as clear the memory.
5.7.1. View Available Memory
MEMORY screen is used to view available memory or to clear the memory. The MEMORY
screen is accessed by selecting MEMORY from the menu. Figure 17 shows the MEMORY
screen.
FREE: 100%
SAMPLES: 6257
PRESS ENTER TO
CLEAR MEMORY!
Figure 17 –Memory Screen
FREE shows the percent of space available for data storage. When 0% is displayed,
memory is full and the oldest data will be overwritten by new data. SAMPLES shows the
number of samples which can be store in memory before the memory is full. When 0%
is displayed, memory is full and the oldest data will be overwritten by new data.
5.7.2. Clearing Memory
To clear memory, press the ENTER key while viewing the MEMORY screen. This will
delete all the sample events in memory. A warning screen will be displayed to prevent
accidental erasure.

AEROCET 531S Manual Rev H Page 20
5.8. Set Flow Screen
The AEROCET 531S has a factory calibrated flow rate of 0.1 CFM (2.83 LPM). Use the
following procedure to adjust the flow rate when a periodic flow rate check (Section 8.3)
indicates a flow rate error greater than +/- 5%.
SET FLOW
< > TO ADJUST
ENTER TO SAVE
███████
Figure 18 –Set Flow Screen
1. Connect a reference flow meter to the inlet fitting on the top of the unit (PN 9801).
2. Access the SET FLOW screen (Figure 18) by pressing MENU then select SET FLOW.
The pump will start automatically when you enter the SET FLOW screen and stop
when you leave the screen.
3. Press ◄ or ► to obtain a reading of 0.1 CFM (2.83 LPM) +/- 5% on the reference
flow meter.
4. Press ENTER to save the setting or ESC to cancel the change.
5.9. Set Clock Screen
To set the date and time select SET CLOCK from the menu. Figure 19 shows the SET
CLOCK screen and the following table describes the date / time formats.
SET CLOCK
DATE: 18 AUG’06
TIME: 11:25:36
Figure 19 –Set Clock Screen
Date / Time Formats
DATE
dd MMM’yy
dd –day, MMM’–month, yy –year
TIME
HH:mm:ss
HH –hours, mm –minutes, ss –seconds