Met One Instruments C-12 User manual

C-12-9800 Rev A Page 1
C-12 Operation Manual - © Copyright 2022 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 without the express written permission of Met One Instruments, Inc.
C-12
BLACK CARBON MONITOR
OPERATION MANUAL
C-12-9800 REV A
Met One Instruments, Inc.
1600 NW Washington Blvd.
Grants Pass, OR 97526
Tel: [phone]
Fax:[phone]
www.metone.com

Page 2 C-12-9800 Rev A

C-12-9800 Rev A Page 3
Table of Contents
1INTRODUCTION 5
1.1 About This Manual 5
1.2 Technical Service 5
1.3 C-12 –Black Carbon Monitor 6
1.4 Safety Warnings 7
1.5 C-12 Instrument Specifications 7
2SITE SELECTION AND POSITIONING CRITERIA 8
3SETUP & DEPLOYMENT 8
3.1 Unpacking 8
3.2 Electrical Service 9
3.3 Shelter & Mounting Options 9
3.4 Sample Inlet Configurations 9
3.5 Assembling the C-12 10
3.6 LED and Toggle Switch User Interface 12
3.6.1 LED Interface 12
3.6.2 Toggle Control Switch Interface 13
3.7 Filter Tape Installation, Loading, and Filter Material Notes 13
3.7.1 Installing Filter Tape 14
3.7.2 Replacing Used Filter Tape 14
3.8 Starting and Stopping Sample Operation 15
3.8.1 Starting Initial Sample Operations 15
3.8.2 Stopping and Resuming Sample Operations 15
4DOWNLOADING AND VIEWING DATA 16
4.1 Web Interface 16
4.1.1 How the Cloud Works 16
4.1.2 Data Retention 17
4.2 Comet Software 17
4.2.1 Comet Installation 18
4.2.2 Setting up a Cloud Station 18
5DATA PLANS AND RENEWALS 20
6REMOTE USER INTERFACE AND MENU SYSTEM 21
6.1 Main Sampling Screens 22
6.2 Menu Hierarchy and Navigation 23
6.3 Start or Stop Sample 23
6.4 Load Tape 24
6.5 View Alarm Log 25
6.6 The SETUP MENU 25
6.6.1 The CLOCK Setup Screen 25
6.6.2 The SAMPLE Setup Screen 26
6.6.3 The MEMORY Setup Screen –Clearing the Memory 26

Page 4 C-12-9800 Rev A
6.7 The CALIBRATE MENU 27
6.7.1 The CALIBRATE FLOW Screens 27
6.7.2 The CALIBRATE AUDIT Screens 27
6.8 The TEST MENU 28
6.8.1 The SELF TEST Screen 28
6.8.2 The TAPE TEST Screen 28
6.8.3 The LEAK TEST Screen 29
6.9 The ADVANCED Menu 29
6.9.1 The CALIBRATE MENU Screen 29
6.9.2 The TEST MENU Screen 29
6.10 The ABOUT Screen 29
7MAINTENANCE AND TROUBLESHOOTING 30
7.1 C-12 Error and Alarm Event Descriptions 30
7.2 Basic Problem Causes/Solutions Table 32
7.3 Suggested Periodic Maintenance Intervals 33
7.4 Flow Audit and Calibration 34
7.4.1 Flow Sensor Calibration 34
7.4.2 Flow Audits 35
7.4.3 The CALIBRATE AUDIT Menu –Performing Optical Span Tests 35
7.5 Flow System Leak Checks 37
7.6 Factory Service Interval 37
8DATA RETRIEVAL AND COMMUNICATIONS 38
8.1 C-12 Data Outputs and Data Examples 38
8.2 Flash Firmware Upgrades 39
9ACCESSORIES AND PARTS 41

C-12-9800 Rev A Page 5
1 INTRODUCTION
1.1 About This Manual
This document is organized with the most important information toward the front of the manual. All
users should read and understand the sections on setup, operation, and field audits. Toward the
back are sections that provide in-depth information on subjects such as diagnostics and
accessories. These sections should be consulted as needed.
This manual is periodically revised for maximum accuracy and to incorporate new features or
updates. User feedback is welcome. An electronic version of this manual is available upon request.
1.2 Technical Service
Should support still be required after consulting the printed documentation, contact one of the
expert Met One Instruments, Inc. 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.
Contact
Information:
Tel: + 541 471 7111
Fax: + 541 471 7116
Web: www.metone.com
Email: [email protected]
Address:
Met One Instruments, Inc.
1600 NW Washington Blvd
Grants Pass, Oregon 97526
U.S.A.
Please have the instrument serial number available when contacting the manufacturer. On most
models manufactured by Met One Instruments, it will be located on a silver product label on the
unit, and also printed on the calibration certificate. The serial number will begin with a letter and be
followed by a unique four or five digit number such as U15915.

Page 6 C-12-9800 Rev A
1.3 C-12 –Black Carbon Monitor
The Met One Instruments, Inc. model C-12 Portable Carbon Monitor is a one-wavelength black
carbon monitor. It automatically measures and records optical transmission across filter media onto
which particulate matter has been deposited. The industry standard wavelength of 880 nm is used
to determine the concentration of black carbon “BC”.Measurement results are sent to a customized
web page dashboard where data can be viewed and downloaded. A geographical map is included
on the dashboard.
Figure 1-1 The C-12
Ambient air is drawn into the instrument at a controlled flow rate. The sampled air is subsequently
drawn through a heated inlet section and then through special glass fiber filter tape, capturing
ambient particulate matter. Optical transmission is measured through the filter tape allowing BC
mass concentrations to be calculated. The filter tape will advance when sufficient particulate matter
has been deposited on the tape to cause the attenuation of the selected channel to exceed a
factory recommended level.
The C-12 also has the option to add a 370 nm illumination channel. Data from the 370 nm and
880 nm channels may be used for source apportionment. Source apportionment allows one to
determine if the measured BC originates from fossil fuel combustion or from biomass combustion.

C-12-9800 Rev A Page 7
1.4 Safety Warnings
Optical Warnings: The C-12 monitor employs an LED light source in the near IR (880 nm) and an
optional source in the near UV (370 nm). Both wavelengths are outside the range of normal human
vision and could present a potential invisible ocular exposure hazard. The near infrared light
source is a 7 mW IR LED emitting at 880 nm. Appropriate precautions should be employed. The
optional UV light source is a 15 mW LED emitting at 370 nm.
A protective housing with this warning symbol fully encapsulates the light
source and optics system during normal operation. Whenever the optical
module is disassembled for service, the power cord must be disconnected to
prevent accidental exposure to IR radiation.
Electrical Warnings: The C-12 is a 12 Volt DC powered system, and there are no hazardous live
voltages located anywhere inside the instrument. It is equipped with an external desktop power
supply module with a 100-240 VAC 50/60 Hz input range, and a 12 VDC, 3.34 A output. The C-12
instrument is housed in a weather-proof case for deployment outdoors.
NOTE: Use ONLY Factory Power Supply. NO SUBSTITUTIONS!
1.5 C-12 Instrument Specifications
PARAMETER
SPECIFICATION
Measurement Principle:
Optical Absorption Wavelength
880 nm BC
370 nm UV (optional)
Measurement Range:
0.01 µg/m3to 100 µg/m3BC
Data Resolution
0.1 ng/m3
LLD:
≤ 70 ng/m3with 1 minute sample time
Measurement Interval:
15 minutes, 15 one-minute samples sent to the cloud
Sample Rate:
1.0 LPM
Filter Tape:
Proprietary treated glass fiber
Operating Temperature:
-20 to +50°C
Internal Data Storage:
2,816 records
Data Download:
Comet Cloud Modem
User Interface:
4 LEDs and toggle switch
Mounting Options:
Pole Mount and Tripod available
Unit Weight:
16 lb 11 oz (7.57 kg)
Unit Dimensions:
15 in (38.1 cm) width x 12 in (30.48 cm) height (to top of sun shield) x 12 in (30.48
cm) depth
Input Power:
100 to 240VAC, 6 W
Specifications may be subject to change without notice. See C-12 datasheet for latest published specs.

Page 8 C-12-9800 Rev A
2 SITE SELECTION AND POSITIONING CRITERIA
There are basic installation requirements for the C-12.There should be adequate cell phone
coverage and an AC power outlet. It can simply be positioned in the area containing the air to be
sampled based on local monitoring needs.
3 SETUP & DEPLOYMENT
The C-12 is designed for easy setup and simple configuration for most applications. This section
describes the basic assembly, setup, and start-up of the instrument.
3.1 Unpacking
Unpack the carbon monitor and accessories and compare them to the packing list to make sure all
items are present.
Any damages 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. Follow any special unpacking instructions provided by the carrier as all items are
carefully removed from the containers and each component inspected. 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.
The instrument is supplied with one of each of the following standard accessories:
•TSP Inlet (part number 9441)
•Inlet Tube (part number 83799)
•USB Cable, A-B male (part number 500784)
•Span Check Membrane (part number 83011)
•Filter Tape, two rolls (part number 83599)
•Operation manual (part number C-12-9800)
Optional Accessories include:
•Mounting Stand (part number 83598)
•Pole Mount (part number 83597)
•Flow Meter (part number Swift 6.0)

C-12-9800 Rev A Page 9
3.2 Electrical Service
The C-12 uses an internal DC power supply which can be supplied with 100 - 240 VAC, 50 or 60
Hz input power. The sampler is rated at 6 Watts maximum continuous power with the sample
pump running. There are no hazardous live voltages located anywhere inside the instrument. The
power supply provides a 12 VDC, 3.34 A output.
NOTE: Use ONLY Factory Power Supply. NO SUBSTITUTIONS!
The sample site needs to be equipped with AC power and a standard weatherproof outdoor
electrical outlet.
For critical applications, where possible sample invalidations due to power failures are
unacceptable, the sampler should be equipped with an uninterruptable power supply (UPS). The
supply must be rated for the electrical load and must be appropriately configured for an outdoor
application. Consult a qualified electrical contractor.
3.3 Shelter & Mounting Options
The C-12 is a weatherproof monitor designed to be mounted on a stand and then deployed in the
outdoors without the need for a shelter or other housing. However, if it is desired, it may also be
installed in an indoor location such as a walk-in shelter, a trailer or mobile lab, a mini outdoor
shelter, or inside of a permanent structure.
Benchtop Mounting: The C-12 may be installed on a table-top. Make sure the mounting surface
is level, and that the instrument is secured so that it won’t “walk” due to vibration.
3.4 Sample Inlet Configurations
The TSP inlet mounts atop the inlet tube. See Figure 3-3.

Page 10 C-12-9800 Rev A
3.5 Assembling the C-12
The C-12 is designed for easy setup and deployment. This allows it to be used for either
permanent long-term sampling at a fixed site or for portable audit sampling for temporary
applications.
Figure 3-1 The C-12 Shown with Optional 83598 Stand
The following describes the standard method of setting up the C-12.
1. Insert the inlet tube: Pull out the lanyard connected fitting from the inlet mount in the top
radiation shield opening. Insert the inlet tube.
2. Connect the TSP Inlet to the inlet: Slide the TSP inlet onto the top of the inlet. Be certain
the TSP inlet is fully seated onto the inlet.
3. Apply power: Plug in the AC power cable.
4. Load filter tape: Open the enclosure and load filter tape into the unit. Filter tape
installation is described in Section 3.7. Close the enclosure.
The C-12 monitor is now ready to begin sampling. See Section 3.8 for initial operation steps

C-12-9800 Rev A Page 11
Figure 3-2 C-12 Internal View
Figure 3-3 C-12 External View
TSP Inlet
Filter Tape
Toggle switch
(4) LED
Indicators
Solar Radiation
Shield
Optional Lock
USB B Serial
Connection
Internal Sample
Tubing
Measurement
Module
Inlet Tube
Modem
Antenna
GPS

Page 12 C-12-9800 Rev A
3.6 LED and Toggle Switch User Interface
The C-12 has a simple user interface on the inside of the unit composed of four LED lights, a
toggle switch (CTRL), and a USB type B serial port (COMM). The LED lights indicate if the sample
is running or not, as well as if there are any errors within the device. The toggle switch can start or
stop the measurement, as well as move the tape.
Figure 3-4 LED and Toggle Switch Interface
3.6.1 LED Interface
Table 3-1 describes the LED light functionality when on and off.
Table 3-1 LED Definitions
LED
OFF
ON
FLASHING
1
Not sampling
Sampling
N/A
2
Transport OK
Failure
Nozzle, Tape Break failure
3
Detector OK
Failure
Detector failure
4
Sensors OK
Failure
Flow, LED T, DET T, AT, or FT out of range

C-12-9800 Rev A Page 13
3.6.2 Toggle Control Switch Interface
Table 3-2 below describes how to move tape, start, and stop a sample with the toggle switch.
Table 3-2 Toggle Control Switch Definitions
Case
Description
How to Start and Stop sample operation
Start
Unit is not Sampling.
Toggle up and hold for >five (5) seconds. This will start sampling and LED 1 will turn ON.
Release the toggle switch when LED 1 is ON.
Note: LED 2 will turn on first after 2 seconds then turn off. Continue to toggle up until
LED 1 lights up.
Stop
Unit is Sampling.
Toggle up and hold for >five (5) seconds. This will stop sampling and LED 1 will turn
OFF. Release the toggle switch when LED 1 is OFF.
The unit will Auto Restart after 30-minutes.
How to move the tape
Tape
Unit is not Sampling.
Toggle up and hold for >two (2) seconds. When LED 2 turns ON release the toggle
switch. The tape move process will begin.
3.7 Filter Tape Installation, Loading, and Filter Material Notes
The C-12 carbon monitor uses treated glass fiber filter tape rolls, available from Met One
Instruments under part number 83599. It is essential that this tape be used in the C-12 in order to
maintain proper instrument calibration and reproducibility. Since the filter tape advance frequency
depends upon filter-loading, the frequency with which the tape needs to be replaced is variable. A
roll of filter tape is expected to last anywhere from 2 to 12 months, depending on the sampling
conditions.
Note: The C-12 tape transport system runs the filter tape from left to right. Notice that this places
the clean roll on the left side of the monitor. This is the opposite of the configuration used in the
Met One Instruments BAM-series monitors.
Warning: The filter tape is rolled with the checker pattern on the outside of the roll, and the softer
side on the inside.

Page 14 C-12-9800 Rev A
3.7.1 Installing Filter Tape
1. Apply power to turn the instrument ON.
2. Hold the toggle switch up for about 2 seconds until the Transport LED turns on, then release
the toggle switch. This will open the measurement module, and a tape move process will
momentarily move the take up reel.
3. Loosen and remove the two tape reel knobs.
4. Install the new filter tape roll onto the left (supply) reel, with the tape coming off the right side
of the roll. Route the tape exactly as shown in Figure 3-5. It should go through the slot in
the measurement module and then to the take-up reel on the right side of the instrument.
Fasten the loose end of the tape to the right edge of an empty spool installed on the take-up
reel, with cellophane tape. Make sure that the softer side is DOWN, and the textured side
is UP.
5. Align the filter tape and take up the slack by turning the left (supply) reel counterclockwise.
6. Hold the toggle switch up for about 2 seconds until the Transport LED turns on, then release
the toggle switch to initiate a tape move. Verify that the tape spools correctly. Repeat this
tape advance sequence until the take up spool rotates at least one full turn.
Figure 3-5 C-12 Filter Tape Routing
3.7.2 Replacing Used Filter Tape
1. Use the toggle switch to open the measurement module, if not already open. See Step 2
above.
2. Loosen and remove the two tape reel knobs.
3. Remove the used tape and spools from the tape reels.
4. Install the new filter tape roll onto the left (supply) reel, with the tape coming off the right side
of the roll. Route the tape exactly as shown in Figure 3-5. It should go through the slot in
the measurement module and then up to the take-up reel on the right side of the instrument.
Fasten the loose end of the tape to the right edge of an empty spool installed on the take-up
reel, with cellophane tape. Make sure that the softer side is DOWN, and the textured side
is UP.
Take-Up Reel
(used filter tape)
Rotates Clockwise
Supply Reel
(clean filter
tape)
Measurement
Module

C-12-9800 Rev A Page 15
5. Align the filter tape and take up the slack by turning the left (supply) reel counterclockwise.
6. Hold the toggle switch up for about 2 seconds until the Transport LED turns on, then release
the toggle switch to initiate a tape move. Verify that the tape spools correctly. Repeat this
tape advance sequence until the take up spool rotates at least one full turn.
3.8 Starting and Stopping Sample Operation
When 12 VDC power is applied to the unit, the C-12 will boot up and get ready to immediately
begin sampling.
3.8.1 Starting Initial Sample Operations
After powering up and starting sampling, the C-12 takes 1 –3 hours to warm up and equilibrate
before optimal measurement stability is achieved.
The C-12 carbon monitor is factory configured with an array of default settings that are appropriate
for most sampling requirements. The operator may consider changing some of these settings
depending on specific requirements. See Section 4 for details about the remote user interface and
the instrument settings.
To start a sample when the unit is stopped, hold the toggle switch up for at least 5 seconds until
the green Sampling LED turns on. The transport LED will briefly turn on after 2 seconds. Continue
to hold the toggle switch up until Sampling LED turns on.
3.8.2 Stopping and Resuming Sample Operations
To stop a sample, hold the toggle switch up for at least 5 seconds until the Sampling LED turns off.
After 30 minutes of inactivity, the unit will automatically resume sampling.

Page 16 C-12-9800 Rev A
4 DOWNLOADING and VIEWING DATA
Currently, Met One offers two options for downloading and viewing the data from a C-12 system: a
Web interface and a windows application. This section will cover both options.
4.1 Web Interface
The first method for downloading and viewing the data is through the Web portal. Each customer
will be senta private link toa custom dashboard in which users can view, chart, and download/export
their data.
4.1.1 How the Cloud Works
The C-12 uses a cloud service for storing and viewing data. After the C-12 collects the data, it
connects to the internet and designated secure Cloud site via its internal cell modem. Once
connected it will push the data to the cloud site. Users may then go to their dashboard and view
their data in gauge, chart, and tabular formats.
Figure 4-1 - C-12 Cloud

C-12-9800 Rev A Page 17
Below is an example dashboard setup:
Figure 4-2 C-12 Website Data Dashboard
Note: Customers are sent a unique web link with their system.
4.1.2 Data Retention
The cloud site stores data for a minimum of 2 years, after which the oldest records may be over-
written. Met One recommends using the Comet utility program to routinely download data and store
the data on a local computer or network. Comet automatically creates a time-stamped, comma
separated CSV data file when data is downloaded. The CSV file can be found in the My Documents
folder. The C-12 unit itself holds 2,816 data records in case of a cloud modem failure.
4.2 Comet Software
The C-12 is compatible with the free copy of the Comet™ program. Comet is a simple, Windows-
based, communications terminal program developed by Met One Instruments, Inc. Comet allows
the user to connect to the cloud and download the data from each cloud service webpage.
The Comet software also contains a comprehensive pdf user’s manual for the program. Install the
program onto the computer you will be using and review the manual for more operational details.
A link to the Comet software is available at https://metone.com/software/.
Comet is a communications terminal program which can retrieve data from the C-12 using
a direct local connection or a remote connection via an IP address or a variety of modem options.
Warning: A Silicon Labs CP210x Driver for the USB connection must be installed before
connecting to the USB Type B port. Driver download weblink:
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

Page 18 C-12-9800 Rev A
4.2.1 Comet Installation
Download the Comet software onto a PC and run the Windows Installer Package. Follow the on-
screen instructions until Comet is successfully installed, then run it from the Programs directory.
Create a new station for the C-12 and use it to retrieve the data from the monitor.
4.2.2 Setting up a Cloud Station
The first time the Comet program is opened it prompts the user to create a new station for your
Cloud site. If Comet does not prompt you, go to the top left menu and select Add New Station to
create a new station.
Select the Cloud Device Product Type and click next. Refer to Figure 4-3.
Figure 4-3 Comet Station Setup

C-12-9800 Rev A Page 19
Select the Met One Cloud Product Type and click next.
Figure 4-4 Comet Product Type Screen
Enter a Station ID, API key, and Serial Number for the C-12.
Figure 4-5 Comet Cloud Information Screen
Note: Customers will receive an API on the provided configuration sheet; a digital copy can be
obtained from the Met One Instruments Service department.

Page 20 C-12-9800 Rev A
Press the Retrieve button to open the Retrieve Data menu screen. When prompted, enter a data
range and press OK to download your station’s data from the cloud.
Figure 4-6 Comet Retrieve Data Screen
Comet will connect to the cloud site and download the device’s data. Users can use the data tab
and chart tab to view the data. When Comet downloads the data, a CSV file is created in the users
My Documents folder.
5 DATA PLANS AND RENEWALS
The C-12 includes one year of cellular data and website hosting at no extra charge. The cloud
service can be renewed by contacting the Met One Service department at [email protected] or
541-471-7111.
The following yearly data plans are available:
680785 CCS Data Plan, 15 Min USA
680786 CCS Data Plan, 5 Min USA
680783 CCS Data Plan, 60 Min Global
680784 CCS Data Plan, 15 Min Global