Met One Instruments GT-521S User manual

GT-521S Manual Rev D
Met One Instruments, Inc
Corporate Sales & Service: 1600 NW Washington Blvd. Grants Pass, OR 97526
Tel [phone] Fax [phone]
www.metone.com [e-mail]
GT-521S
MANUAL

GT-521S Manual Rev D Page 1
Copyright Notice
GT-521S 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 GT-521S. 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.
Contact
Information:
Tel: [phone]
Fax: [phone]
Web: www.metone.com
Email: servi[email protected]m
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.
Table of Contents

GT-521S Manual Rev D Page 2
1. Introduction........................................................................................................... 4
2. Setup...................................................................................................................... 4
2.1. Unpacking..................................................................................................................................4
2.2. Layout........................................................................................................................................7
2.3. Default Settings .........................................................................................................................8
2.4. Initial Operation .........................................................................................................................8
3. User Interface ........................................................................................................ 8
4. Operation............................................................................................................... 9
4.1. Power Up...................................................................................................................................9
4.2. Operate Screen .........................................................................................................................9
4.2.1. Sampling ...........................................................................................................................10
4.2.2. Sample Status...................................................................................................................10
4.2.3. Sample History..................................................................................................................10
4.2.4. Warning / Error Messages ................................................................................................11
4.3. Sample Related Functions ......................................................................................................11
4.3.1. Starting/Stopping...............................................................................................................11
4.3.2. Real-Time Serial Output ...................................................................................................11
4.3.3. Samples ............................................................................................................................11
4.3.4. Sample Time.....................................................................................................................11
4.3.5. Hold Time..........................................................................................................................11
4.3.6. Count Mode.......................................................................................................................12
4.3.7. Sample Timing..................................................................................................................12
5. Menu Selections.................................................................................................. 13
5.1. Edit Menu Items.......................................................................................................................13
5.2. Sample Setup Screen..............................................................................................................13
5.2.1. Location Number...............................................................................................................14
5.2.2. Sample Time.....................................................................................................................14
5.2.3. Hold Time..........................................................................................................................14
5.2.4. Samples ............................................................................................................................14
5.3. Settings Screen .......................................................................................................................14
5.3.1. Volume..............................................................................................................................14
5.3.2. Temperature......................................................................................................................15
5.3.3. Count mode.......................................................................................................................15
5.4. Recall Data Screen..................................................................................................................15
5.5. Print Data Screen ....................................................................................................................16
5.6. Memory Screen .......................................................................................................................16
5.6.1. View Available Memory.....................................................................................................17
5.6.2. Clearing Memory...............................................................................................................17
5.7. Count Alarms Screen ..............................................................................................................17
5.7.1. Alarm Analog Output.........................................................................................................18
5.8. Serial........................................................................................................................................18
5.8.1. Report Type ......................................................................................................................18
5.8.2. Baud..................................................................................................................................18

GT-521S Manual Rev D Page 3
5.8.3. Serial Output Mode...........................................................................................................19
5.9. Set Flow Screen ......................................................................................................................19
5.10. Set Sizes Screen.....................................................................................................................19
5.11. Set Clock Screen.....................................................................................................................20
5.12. Set Contrast Screen ................................................................................................................20
5.13. About Screen...........................................................................................................................20
6. Charging the Battery........................................................................................... 21
7. Serial Communications ...................................................................................... 22
7.1. Serial Interface ........................................................................................................................23
7.2. Commands ..............................................................................................................................24
7.3. Real Time Output ....................................................................................................................24
7.4. Comma Separated Value (CSV) .............................................................................................25
7.5. Printer Format..........................................................................................................................25
8. Maintenance ........................................................................................................ 26
8.1. Service Schedule.....................................................................................................................26
8.2. Zero Count Test.......................................................................................................................26
8.3. Flow Rate Test.........................................................................................................................26
8.4. Annual Calibration ...................................................................................................................26
8.5. Flash Upgrade.........................................................................................................................27
9. Troubleshooting.................................................................................................. 27
10. Specifications...................................................................................................... 28
11. Warranty / Service............................................................................................... 29

GT-521S Manual Rev D Page 4
1. Introduction
The GT-521S is a full–featured, two-channel, battery operated, handheld particle
counter. The two count channels can be configured to factory calibrated standard sizes
or user defined custom sizes. It also has two alarm limits and various communication
options. This instrument can store up to 8,000 sample events including data from the
optional temperature / relative humidity probe (PN G3120). Sample history events can
be viewed on the LCD display, printed on the optional printer (PN G3115) and
downloaded 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.

GT-521S Manual Rev D Page 5
ATTENTION:
The included USB drivers must be installed before connecting the GT-521S 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.
Users using a 32 bit system should install the USB 32 bit drivers. Users using a 64 bit
system should install the USB 64 bit drivers.

GT-521S Manual Rev D Page 6
Figure 1 –Standard Accessories
Figure 2 –Optional Accessories
GT-521S Standard Equipment
GT-521S
PN GT-521S
Battery Charger
PN 390031
Power Cord
PN 400113
Carrying Case
PN 8517
Calibration Certificate
PN GT-521S-9600
ISO-Kinetic Probe
PN G3110
Zero Count Filter
PN G3111
USB Cable
PN 500787
Comet Software CD
PN 80248
Manual
PN GT-521S-9800
Printer
PN G3115
Flow Meter
PN 9801
Serial Cable
PN 3228
T/RH Probe
PN G3120

GT-521S Manual Rev D Page 7
2.2. Layout
The following figure shows the layout of the GT-521S and provides a description of
each of the components.
Figure 3 –GT-521S Layout
Component
Description
Power Switch
Switch that turns the GT-521S 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).
T/RH Connector
Mating connector for the optional external Temperature/RH sensor.
Inlet Nozzle
Ambient air inlet nozzle. Connect isokinetic probe to reduce
turbulence in the air sample.
Charging Jack
Isokinetic Inlet Probe
T/RH Connector
USB Port
Serial Port
Power Switch
Inlet Nozzle (remove cap)

GT-521S Manual Rev D Page 8
2.3. Default Settings
The GT-521S comes with the user settings configured as follows.
Parameter
Value
Sizes
0.3 µm and 0.5 µm
Sample Location
1
Samples
Single
Sample Time
60 seconds
Sample Hold Time
0 seconds
Volume (concentration)
CF (particles/ft3)
Count Mode
Normal (cumulative)
Temperature Units
C
Baud Rate
9600
Serial Mode
RS-232
Alarm Limits
Disabled
2.4. Initial Operation
Before operating the GT-521S 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 power.
2. Observe the Startup Screen for 2 seconds then the Operate Screen (Section
4.2).
3. Press Start / Stop key. The GT-521S will sample for 1 minute and stop.
4. Observe the counts on the display.
5. The unit is ready for use
3. User Interface
The GT-521S 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 editing a field.
Loads the Operate Screen when in the Menu Screen.
Cancels editing a field 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.
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

GT-521S Manual Rev D Page 9
4. Operation
The following sections cover the basic operation.
4.1. Power Up
GT-521S 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.
GT-521S
WWW.METONE.COM
Figure 4 –Startup Screen
4.2. Operate Screen
The Operate Screen displays the date/time, sample status, current sample data and
previous sample data. Figure 5 shows the Operate Screen.
18 AUG’06 11:23
0.3µ 0 CF
0.5µ 0 CF
Location: 001
Figure 5 –Operate Screen w/o Temp/RH
The top line of the Operate Screen shows date and time or status/alarm messages
depending upon the machine status. Lines 2 and 3 display the two count channels.
Line 4 displays the location number or optional Temp/RH data. Use the up/down arrows
to alternate between Location number and Temp/RH when the optional G3120 probe is
attached.
Particle count units are user selectable. The selections include: Total counts (TC),
particles per liter (/L), particles per cubic foot (CF) and particles per cubic meter (M3).
Ambient temperature can be displayed in units of Celsius (ºC) or Fahrenheit (ºF). Both
unit settings are discussed in section 5.2.4.

GT-521S Manual Rev D Page 10
4.2.1. Sampling
The Operate Screen displays current sample information when the unit is sampling (real
time data). 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. Longer samples (e.g. 60 seconds) will improve concentration measurement
accuracy. Figure 6 shows the Operate Screen while sampling.
COUNTING... 52
0.3µ29,780 CF
0.5µ1,400 CF
Location: 001
Figure 6 –Operate Screen Sampling
4.2.2. Sample Status
The top line of the Operate Screen displays the status of the GT-521S while the unit is
sampling. The following table shows the various status messages:
Status
Description
STARTING…
GT-521S is starting the sample and is waiting for the count
system to initialize.
HOLDING…
GT-521S is taking multiple samples and is waiting for the hold
time to finish.
STOPPING…
GT-521S is stopping the sample and is waiting for the count
system to stop.
COUNTING… 10
GT-521S is sampling. The time remaining is displayed on the far
right.
4.2.3. 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 Enter 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 7) to indicate history data, and displays
the date and time stamp when the sample was collected. 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.
18 AUG’06 11:23
0.3µ 0 CF
0.5µ 0 CF
Location: 001
Figure 7 –History Screen

GT-521S Manual Rev D Page 11
4.2.4. Warning / Error Messages
The GT-521S displays warning/error messages on the top line of the Operate Screen.
These messages alternate with the normal header. The following table lists the
warning/error messages:
Display Message
Description
<COUNT ALARM>
Count alarm. The count is the alarm limit.
LOW BATTERY!
Low battery warning. Less than 15 minutes of normal operation remaining.
SENSOR ERROR!
Particle sensor error.
4.3. Sample Related Functions
The following sub-sections cover sample related functions.
4.3.1. 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.
4.3.2. Real-Time Serial Output
GT-521S provides real-time output on the serial port at the end of each sample. The
format of the output is controlled by the report type setting (section 5.8.1).
4.3.3. Samples
The Samples setting controls the number of samples to take. Repeat configures the unit
for continuous sampling. Single configures the unit for a single sample. 2-999
configures the unit for a number of samples. Samples are discussed in section 5.2.
4.3.4. Sample Time
The sample time determines the amount of time that counts are accumulated. The
length of the sample is user settable from 1 –9999 seconds and is discussed in section
5.2.
4.3.5. Hold Time
The hold time is used when Samples is set for more than one 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 –9999 seconds and is discussed in
section 5.2.

GT-521S Manual Rev D Page 12
4.3.6. Count Mode
The count mode is used to set whether counts are displayed as Cumulative (normal) or
Differential. When in differential mode, the volume units will be preceded with the delta
character Δ. Count mode is discussed in more detail in section 5.3.
COUNTING... 58
0.3µ29,780 ΔCF
0.5µ1,400 ΔCF
Location: 001
Figure 8 –Differential Counts
4.3.7. Sample Timing
The following figures depict the sample timing sequence for both single and multiple
samples. Figure 9 shows the timing for single samples. Figure 10 shows the timing for
multiple samples.
Figure 9 –Single Sample
Figure 10 –Multiple Samples
Start
Time Sample Time Stop
Time
Start
Time Sample Time Hold Time Sample Time Stop Time

GT-521S Manual Rev D Page 13
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
SAMPLE SETUP
View / change location number, sample time, hold time and samples.
SETTINGS
View / change volume (count units), ºC / ºF and Count mode (Normal
or Difference)
RECALL DATA
Recall sample history based on time
PRINT DATA
Print stored data based on a time range.
MEMORY
View memory usage and clear memory.
COUNT ALARMS
Set count alarm limits for 2 particle sizes
SERIAL
Set output report type, baud rate and serial output mode
SET FLOW
Adjust the sample flow rate
SET SIZES
Set particle sizes
SET CLOCK
Set the date and time.
SET CONTRAST
Adjust the display contrast.
ABOUT
Display firmware version and serial number.
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. Settings Temp –C/F), 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 previous value.
To edit numeric values (e.g. Count Alarms - Alarm Limit), 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 previous value.
5.2. Sample Setup Screen
Figure 11 shows the Sample Setup Screen. The four parameters are covered in the
following sections.
LOCATION: 001
SAMPLE TIME: 0060
HOLD TIME: 0000
SAMPLES: SINGLE
Figure 11 –Sample Setup Screen

GT-521S Manual Rev D Page 14
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 serial output).
5.2.2. Sample Time
The sample time determines the amount of time that counts are accumulated while the
pump is running. The length of the sample is user settable from 1 –9999 seconds.
5.2.3. Hold Time
The Hold time is the time between samples when sampling more than a single sample.
The Hold time is user settable from 0 –9999 seconds. The pump will remain on during
the hold period if the Hold time is 60 seconds or less. If the Hold time is greater than 60
seconds, the pump will stop after each sample, and start a few seconds before the next
sample. Hold times greater than 60 seconds will increase pump life.
5.2.4. Samples
The samples setting controls the number of samples to take as illustrated below.
Selection
Description
REPEAT
Repeat configures the unit for continuous sampling.
SINGLE
Single configures the unit for a single sample.
002-999
Configures the unit to take N samples.
5.3. Settings Screen
Figure 12 shows the Settings Screen. The four parameters are covered in the sections
immediately following.
VOLUME: CF
TEMP: C
COUNT NORMAL
Figure 12 –Settings Screen
5.3.1. Volume
The GT-521S 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. Longer samples (e.g. 60 seconds) will improve concentration measurement
accuracy. In total count mode, counts accumulate throughout the sample time.

GT-521S Manual Rev D Page 15
5.3.2. Temperature
The GT-521S displays temperature in Celsius (C) or Fahrenheit (F).
5.3.3. Count mode
The GT-521S can display counts in two different modes. These are Normal and
Differential.
Selection
Description
NORMAL
Displays cumulative counts on the screen and in reports.
DIFFERENCE
Displays differential counts on the screen and in reports.
The Normal mode displays cumulative counts. For a given size the counts represent all
particles that size and larger.
The Differential mode displays the number of particles between a given size and the
size larger. When in differential mode, the volume units will be preceded the delta
character Δon the screen. For the serial output a lower case ‘d’ character is displayed
in the header.
COUNTING... 58
0.3µ29,780 CF
0.5µ1,400 CF
Location: 001
Figure 13 –Cumulative Counts
COUNTING... 58
0.3µ28,380 ΔCF
0.5µ790 ΔCF
Location: 001
Figure 14 –Differential Counts
5.4. 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 15 shows the
Recall Data Screen.
RECALL DATA
01 JAN’00 00:00
Figure 15 –Recall Data Screen

GT-521S Manual Rev D Page 16
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. Use ◄ or ► to navigate through the stored sample events.
5.5. Print Data Screen
Stored sample events can be printed through the printer port within a user selected
range. To print selected data, select PRINT DATA from the Menu. Figure 16 shows the
Print Data Screen.
PRINT DATA
LOCATION: 000
01 JAN’00 00:00
18 AUG’06 13:23
Figure 16 –Print Data Screen
Edit the location and time range to select which sample events to print. The following
table describes settings.
Setting
Description
LOCATION
The location ID of the sample events to print. Setting location
to 000 prints all locations. Settable from 0 - 999
01 JAN’00
The date/time to begin printing sample events from.
18 AUG’06
The date/time to stop print samples at.
After the print settings have been selected, press the Start/Stop button to begin printing
the sample events. Once the Start/Stop button has been pressed the Printing Status
Screen is displayed. Figure 17 shows the Printing Status Screen as it would look when
finished.
PRINTING STATUS
SCANNING...15
PRINTING...10
FINISHED!
Figure 17 –Printing Status Screen
Pressing the ESC button cancels the data printing and loads the menu. The format of
the print is dependent upon the report type setting (Section 5.8.1)
5.6. Memory Screen
The GT-521S memory is composed of a single file which contains the data from sample
events. Every time a sample is completed, the GT-521S stores that data into the
memory. The GT-521S memory is circular, meaning when the memory is full, the unit
will start overwriting the oldest saved samples with new samples. GT-521S provides
the user the ability to view the memory usage as well as clear the memory.

GT-521S Manual Rev D Page 17
5.6.1. 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 18 shows the
Memory Screen.
FREE: 100%
SAMPLES: 8000
PRESS ENTER TO
CLEAR MEMORY!
Figure 18 –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 stored in memory before the
memory is full. When 0 is displayed, memory is full and the oldest data will be
overwritten.
5.6.2. 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.
5.7. Count Alarms Screen
Configure count alarm limits for two particle sizes. To disable count alarms, select OFF
in the field next to the COUNT ALARM header. The alarm for a specific particle size can
be disabled by setting the alarm value to zero. The alarm is active when the count is
equal to or greater than the alarm limit. The maximum alarm limit value is 9,999,999.
Figure 19 shows the Count Alarm Screen.
Alarm values do not change with the count units setting (TC, /L, CF, M3). In other
words, a value of 1,000 will alarm at 1,000 counts or 1,000 particles per liter or 1,000
particles per cubic foot depending on the count unit setting.
COUNT ALARMS OFF
SIZE ALARM LIMIT
0.3 00000000
0.5 00000000
Figure 19 –Set Alarms Screen

GT-521S Manual Rev D Page 18
5.7.1. Alarm Analog Output
Along with the two channel alarms mentioned in section 5.7, there is also an alarm level
analog output for each channel. The analog output is always active and it is not tied to
the alarm logic being on or off. The table below shows the analog output levels for each
alarm. The analog out is available on the DB-9 Serial connector on the right side of the
instrument. See section 7.1 for details.
Channel
Alarm Type
Analog Output
Channel 1
No Alarm
0.00 V
Channel 1
Hi Alarm
5.00 V
Channel 2
No Alarm
0.00 V
Channel 2
Hi Alarm
5.00 V
5.8. Serial
Configure the serial port settings.
REPORT: CSV
BAUD: 9600
SERIAL: RS-232
Figure 20 –Serial Screen
5.8.1. Report Type
The Report setting determines the output format for the Serial Port. The choices are
NONE, CSV and PRINTER.
When set to NONE, the unit will not automatically output the reading at the end of a
sample to the Serial Port. CSV is a Comma Separated Values output format suitable
for importing into a spreadsheet. PRINTER is the same format as the screen and
optional external printer.
Note: When using the optional external printer, set the report type to PRINTER.
5.8.2. Baud
Use the Baud Rate selection to set the serial communications baud rate. GT-521S
communicates at baud rates from 300 –38400. The default baud rate is 9600.

GT-521S Manual Rev D Page 19
5.8.3. Serial Output Mode
The Serial Output Mode setting controls the behavior of the GT-521S serial output. The
modes are RS-232 and RS-485. The following table lists the Serial Output settings and
describes their meanings.
Serial
Setting
Description
RS-232
RS-232/USB serial communication with CSV style output.
Records automatically transmitted after each sample.
RS-485
RS-485 communication with CSV style output.
5.9. Set Flow Screen
The GT-521S 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%.
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 21) 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.
SET FLOW
< > TO ADJUST
ENTER TO SAVE
███████
Figure 21 –Set Flow Screen
5.10. Set Sizes Screen
The GT-521S has factory calibrated particle sizes (for example, 0.3, 0.5, 1.0, 5.0 and 10
µm). These standard sizes will support most applications and provide the best size
accuracy (± 10%). This unit also supports custom sizes. These sizes are configured
using the Set Sizes Screen (Figure 22). Custom sizes are interpolated using the
standard size calibration curve. Therefore, the size accuracy for custom sizes is
somewhat reduced (± 15%).
SET SIZES
CH1: 00.3µ
CH2: 00.5µ
Figure 22 –Set Sizes Screen