BioFiltro Flux Measurements Logger

Program for obtaining meteorological and greenhouse gas (GHG) data from the sensors listed in the table below using a CR1000 datalogger. Data can be monitored in real-time using the LoggerLink app on a phone or tablet while connected to the trailer's wireless local area network. A user-controlled processing flag allows for automatic data reduction of measurements made during a sampling run. Raw measurements are also stored in separate data tables to permit in-depth analysis.

Specific instruments include:

• N₂O/CO trace gas analyzer (DLT-100 series; Los Gatos Research)
  • Nitrous oxide
  • Carbon monoxide
  • Water vapor
• CH₄/CO₂ trace gas analyzer (UGGA; Los Gatos Research)
  • Methane
  • Carbon dioxide
  • Water vapor
• Total weather station (WXT510; Vaisala)
  • Horizontal wind speed & direction
  • Ambient temperature & relative humidity
  • Barometric pressure
  • Precipitation accumulation (rain & hail)
• Photosynthetically active radiation (PAR) sensor (LI-190SA; LI-COR Biosciences)
• GPS receiver (for clock sync) (GPS16X-HVS; Garmin)

Setup

Power

Connect trailer power cords to appropriate power sources:

Cord type	Circuit	Min. breaker size
Orange, parallel blade plug	#1, for analyzers	15A
Black, T-blade plug	#2, for air conditioner	20A

Air conditioner

Turn on the A/C to Cool mode and set temperature to room temp (72°C or cooler).

Gas analyzers

Refer to manufacturer user guides for complete setup details. Be sure to:

1. Turn on the uninterruptible power supply (hold the power button for 3-5 seconds) before turning on the two trace gas analyzers.
2. Verify connections for sampling plumbing before plugging in the flushing pump (see diagram below).
3. Verify serial data cables are connected to analyzers.
4. Verify analyzers are configured as described in Configuration section.

Weather station & PAR sensor

The weather station and PAR sensor are mounted on the side of the trailer. Once the trailer is positioned, remove protective covers items and verify sensors are correctly deployed so that:

• the weather station is approximately level,
• the weather station is pointing northward (to avoid shading the PAR sensor), and
• the PAR sensor is also level

If the weather station is not oriented exactly to geographic (True) north, the actual azimuth should be updated in the logger program. See the Operations section.

A short step ladder may be required to level the PAR sensor. Refer to the sensor user manual for mounting plate leveling instructions.

Datalogger

Turn on the battery-backed power supply in the datalogger enclosure to enable the logger (also the weather station and datacom equipment).

Review and update the following program constants before the start of sampling. They can be modified using the handheld keyboard display, or by updating the public Constants table named "Constants" and triggering a restart.

• UTC_OFFSET - time offset relative to UTC, in hours (default: -8 = Pacific Standard Time)
• PAR_MULT - unique sensor-specific calibration value, in µmol/(mV s m²) (default: -197.63)

The following program variable must also be updated when the weather station is installed and anytime it's adjusted. The variable can be updated by changing itsvalue in the data table named "Public". Changes go into effect immediately without any program restarts.

• WXT_AZIMUTH - orientation of the weather station w.r.t. True North, in degrees (default: 0 = True North)

Operations

LoggerLink

The no-cost mobile app LoggerLink is the recommended datalogger interface. Connect to the trailer's wireless network and use the search feature, or use the following setup details to create a new connection manually:

• Address: 192.168.13.50
• Port: 6785 (default)
• Type: CR1000
• Pakbus Address: 1 (default)
• Security code: update to match logger configuration

Note if the security code does not match the logger, data may still be viewable but public variables will not be editable and therefore triggering sample runs will not be allowed.

Alternatively, a handheld keyboard display (CR1000KD; Campbell Scientific) can be used instead. The main disadvantages of the keyboard display are (1) lack of interactive data plotting, and (2) being physically constrained by the display's cable length.

RealVNC

It is also recommended to have VNC Viewer or other VNC-compatible client for remotely viewing and controlling the two trace gas analyzers. Launch the client and create a new connection for each one:

Device	IP Address	Port	Password†
N2O/CO analyzer	192.168.13.51	5900	lgrvnc
CH4/CO2 analyzer	192.168.13.52	5900	lgrvnc

†If the default doesn't work, check the notes in the device user manual.

Real-time Monitoring

The recommended method for viewing individual data values is the Current interface of LoggerLink.

1. Open settings (gear icon)
2. Select a data table
   • Choose biofiltro_1hz for unprocessed (raw) data from the trace gas analyzers
   • Choose biofiltro_wxt for unprocessed (raw) data from the weather station
   • Choose biofiltro_1min for 1-min averages of weather station, PAR sensor, and temperature data
   • Choose biofiltro_runs for data saved from the last sampling run
   • Choose Public for the most recent values of run duration, internal datalogger temperature, and temperature of air coming from the AC unit
3. Select relevant fields, as desired.

Real-time Plotting

The recommended method for plotting data is the Historical interface of LoggerLink.

1. Select up to several individual fields from a single data table
2. Specify the data range (from minutes up to weeks)
3. Optionally configure display formatting for individual fields:
   • Left or right axis
   • Display as line, points, or line + points
   • Set line width / color / styling
   • Set point size / color / shape

Triggering Sample Runs

Users can capture and reduce data over a particular time window using the public field run_flag. When that field is set to True, a new output interval is created and measurements are included for intermediate processing. When the run_flag field is reset to False, final processing occurs and a new record is stored in data table "biofiltro_runs".

• To begin a sample run, change the public field run_flag to True.
• To end a sample run and compute run statistics, change the public field run_flag to False.

The public field run_flag can be easily modified using the Current screen of the LoggerLink app...

1. Ensure the "Public" table is selected and all fields are shown.
2. Press and hold the run_flag field.
3. In the resulting Change Value dialog, update the value and press [OK] to save changes.
   • To begin a run, set the value to True
   • To end the run, set the value to False

...or with a local keyboard display:

1. Press any key to wake up the keyboard display.
2. Verify the cursor selection is "Run flag".
3. Press [Enter] to modify the current value.
4. Select the desired value and press [Enter] to save changes.
   • To begin a run, set the value to True
   • To end the run, set the value to False

Data Products

Table Summary

Table name	Record interval	Storage capacity	Description
biofiltro_runs	user-defined	100 records	User-triggered aggregates of GHG and meteorological measurements, for final data analysis.
biofiltro_1hz	1 second	14 days	Raw measurements from Los Gatos Research analyzers, for real-time data monitoring and quality control.
biofiltro_1min	1 minute	14 days	1-min aggregates of meteorological and instrument temperature measurements, for real-time data monitoring.
biofiltro_gps	1 minute	14 days	Raw measurements from GPS receiver, for quality control.
biofiltro_wxt	5 seconds	14 days	Raw measurements from weather station, for quality control.

All tables are configured in Ring memory mode such that upon reaching capacity, newly generated records will overwrite the oldest records in storage.

biofiltro_runs

Statistical summary of data captured during a user-triggered run events. Duration of each data record is reported in field run_duration. Up to 100 events are stored before old data is overwritten.

Field name	Units	Instruction	Description
TIMESTAMP	TS	-	Machine-formatted timestamp (YYYY-MM-DD hh:mm:ss)1
RECORD	RN	-	Sequential record number
UTC_OFFSET	hours	Average	Clock timezone offset relative to UTC2
run_duration	seconds	Sample	Duration of sample run
lgr_CO_Avg	ppb	Average	Mean mixing ratio of carbon monoxide
lgr_CO_Std	ppb	StdDev	Standard deviation of mixing ratio of carbon monoxide
lgr_N2O_Avg	ppb	Average	Mean mixing ratio of nitrous oxide
lgr_N2O_Std	ppb	StdDev	Standard deviation of mixing ratio of nitrous oxide
lgr_H2O_Avg	ppm	Average	Mean mixing ratio of water vapor
lgr_H2O_Std	ppm	StdDev	Standard deviation of mixing ratio of water vapor
lgr_CO_dry_Avg	ppb (dry)	Average	Mean mixing ratio (dry) of carbon monoxide
lgr_CO_dry_Std	ppb (dry)	StdDev	Standard deviation of mixing ratio (dry) of carbon monoxide
lgr_N2O_dry_Avg	ppb (dry)	Average	Mean mixing ratio (dry) of nitrous oxide
lgr_N2O_dry_Std	ppb (dry)	StdDev	Standard deviation of mixing ratio (dry) of nitrous oxide
lgr_cell_P_Avg	Torr	Average	Mean sample cell pressure of LGR N2O/CO analyzer
lgr_cell_P_Std	Torr	StdDev	Standard deviation of sample cell pressure of LGR N2O/CO analyzer
lgr_cell_T_Avg	degC	Average	Mean sample cell temperature of LGR N2O/CO analyzer
lgr_cell_T_Std	degC	StdDev	Standard deviation of sample cell temperature of LGR N2O/CO analyzer
lgr_self_T_Avg	degC	Average	Mean internal temperature of LGR N2O/CO analyzer
lgr_self_T_Std	degC	StdDev	Standard deviation of internal temperature of LGR N2O/CO analyzer
ugga_CH4_Avg	ppm	Average	Mean mixing ratio of methane
ugga_CH4_Std	ppm	StdDev	Standard deviation of mixing ratio of methane
ugga_CO2_Avg	ppm	Average	Mean mixing ratio of carbon dioxide
ugga_CO2_Std	ppm	StdDev	Standard deviation of mixing ratio of carbon dioxide
ugga_H2O_Avg	ppm	Average	Mean mixing ratio of water vapor
ugga_H2O_Std	ppm	StdDev	Standard deviation of mixing ratio of water vapor
ugga_CH4_dry_Avg	ppm (dry)	Average	Mean mixing ratio (dry) of methane
ugga_CH4_dry_Std	ppm (dry)	StdDev	Standard deviation of mixing ratio (dry) of methane
ugga_CO2_dry_Avg	ppm (dry)	Average	Mean mixing ratio (dry) of carbon dioxide
ugga_CO2_dry_Std	ppm (dry)	StdDev	Standard deviation of mixing ratio (dry) of carbon dioxide
ugga_cell_P_Avg	Torr	Average	Mean sample cell pressure of LGR CH4/CO2 analyzer
ugga_cell_P_Std	Torr	StdDev	Standard deviation of sample cell pressure of LGR CH4/CO2 analyzer
ugga_cell_T_Avg	degC	Average	Mean sample cell temperature of LGR CH4/CO2 analyzer
ugga_cell_T_Std	degC	StdDev	Standard deviation of sample cell temperature of LGR CH4/CO2 analyzer
ugga_self_T_Avg	degC	Average	Mean internal temperature of LGR CH4/CO2 analyzer
ugga_self_T_Std	degC	StdDev	Standard deviation of internal temperature of LGR CH4/CO2 analyzer
WindSpeed_Avg	m/s	WindVector	Mean horizontal wind speed
WindDir_vector_Avg	degrees	WindVector	Unit vector mean wind direction
WindDir_Std	degrees	WindVector	Standard deviation of wind direction (Yamartino algorithm)3
WXT_AZIMUTH_Avg	degrees	Average	Orientation (azimuth) of weather station relative to True North4
Tmpr_Avg	degC	Average	Mean ambient air temperature
RH_Avg	percent	Average	Mean ambient relative humidity
Press_Avg	hPa	Average	Mean barometric pressure
Press_Std	hPa	StdDev	Standard deviation of barometric pressure
Rain_amt_Tot	mm	Totalize	Total rain accumulation
Hail_amt_Tot	hits/cm^2	Totalize	Total hail accumulation
HeaterTmpr_Avg	degC	Average	Mean weather station heater element temperature
HeaterVolts_Avg	Vdc	Average	Mean weather station heater power source5
PAR_density_Avg	umol/(s m^2)	Average	Mean photosynthetic photon flux density (PPFD), approximately6
PAR_density_Std	umol/(s m^2)	StdDev	Standard deviation of photosynthetic photon flux density (PPFD), approximately6
PAR_MULT_Avg	umol/(mV s m^2)	Average	Calibration factor for PAR sensor7
LoggerTmpr_Avg	degC	Average	Mean internal temperature of datalogger
AC_Tmpr_Avg	degC	Average	Mean temperature of air coming from AC unit

Footnotes:

1. Timestamp marks end-of-intervals. To calculate run start time, subtract run_duration from TIMESTAMP.
2. Corresponds to user-defined constant UTC_OFFSET. A non-integer value indicates value was modified during the record interval.
3. "This option complies with EPA guidelines for use with straight-line Gaussian dispersion models to model plume transport." [CRBasic Program Reference, version CR1000.Std.32.05]
4. Stored wind directions include this constant offset value; it's computed as an average and stored separately here for data quality purposes (e.g. to identify if/when azimuth value was changed).
5. Available, not applied, heating voltage. Refer to WXT510 user manual for heater operation details.
6. “Approximately” because the PAR sensor is over a decade past its recommended calibration interval. Value should be negative per manufacturer guidelines for usage with millivolt adapter module.
7. The multiplier is calculated as an average to help identify if/when the value was updated.

biofiltro_1hz

Raw measurements from the Los Gatos Research trace gas analyzers.

Field name	Units	Instruction	Description
TIMESTAMP	TS	-	Machine-formatted timestamp (YYYY-MM-DD hh:mm:ss)
RECORD	RN	-	Sequential record number
lgr_CO	ppb	Sample	Mixing ratio of carbon monoxide
lgr_N2O	ppb	Sample	Mixing ratio of nitrous oxide
lgr_H2O	ppm	Sample	Mixing ratio of water vapor
lgr_CO_dry	ppb (dry)	Sample	Mixing ratio (dry) of carbon monoxide
lgr_N2O_dry	ppb (dry)	Sample	Mixing ratio (dry) of carbon monoxide
lgr_cell_P	Torr	Sample	Cell pressure of LGR N2O/CO analyzer
lgr_cell_T	degC	Sample	Cell temperature of LGR N2O/CO analyzer
lgr_self_T	degC	Sample	Internal temperature of LGR N2O/CO analyzer
ugga_CH4	ppm	Sample	Mixing ratio of methane
ugga_CO2	ppm	Sample	Mixing ratio of carbon dioxide
ugga_H2O	ppm	Sample	Mixing ratio of water vapor
ugga_CH4_dry	ppm (dry)	Sample	Mixing ratio (dry) of methane
ugga_CO2_dry	ppm (dry)	Sample	Mixing ratio (dry) of carbon dioxide
ugga_cell_P	Torr	Sample	Cell pressure of LGR CH4/CO2 analyzer
ugga_cell_T	degC	Sample	Cell temperature of LGR CH4/CO2 analyzer
ugga_self_T	degC	Sample	Internal temperature of LGR CH4/CO2 analyzer

biofiltro_1min

Weather station, PAR sensor, and temperature data reduced to one-minute statistical values.

Field name	Units	Instruction	Description
TIMESTAMP	TS	-	Machine-formatted timestamp (YYYY-MM-DD hh:mm:ss)
RECORD	RN	-	Sequential record number
WindSpeed_Avg	m/s	WindVector	Mean horizontal wind speed
WindDir_vector_Avg	degrees	WindVector	Unit vector mean wind direction1
WindDir_Std	degrees	WindVector	Standard deviation of wind direction (Yamartino algorithm)2
WXT_AZIMUTH_Avg	degrees	Average	Orientation (azimuth) of weather station relative to True North3
Tmpr_Avg	degC	Average	Mean ambient air temperature
RH_Avg	percent	Average	Mean ambient relative humidity
Press_Avg	hPa	Average	Mean barometric pressure
Rain_amt_Tot	mm	Totalize	Total rain accumulation
Hail_amt_Tot	hits/cm^2	Totalize	Total hail accumulation
HeaterTmpr_Avg	degC	Average	Mean weather station heater element temperature
HeaterVolts_Avg	Vdc	Average	Mean weather station heater power source4
PAR_density_Avg	umol/(s m^2)	Average	Mean photosynthetic photon flux density (PPFD), approximately5
PAR_MULT_Avg	umol/(mV s m^2)	Average	Calibration factor for PAR sensor5
LoggerTmpr_Avg	degC	Average	Mean internal temperature of datalogger
AC_Tmpr_Avg	degC	Average	Mean temperature of air coming from AC unit
lgr_cell_T_Avg	degC	Average	Mean temperature of sample cell in Los Gatos Research N2O/CO analyzer
lgr_self_T_Avg	degC	Average	Mean internal temperature of Los Gatos Research N2O/CO analyzer
ugga_cell_T_Avg	degC	Average	Mean temperature of sample cell in Los Gatos Research CH4/CO2 analyzer
ugga_self_T_Avg	degC	Average	Mean internal temperature of Los Gatos Research CH4/CO2 analyzer

Footnotes:

1. Includes constant offset value WXT_AZIMUTH.
2. "This option complies with EPA guidelines for use with straight-line Gaussian dispersion models to model plume transport." [CRBasic Program Reference, version CR1000.Std.32.05]
3. Stored wind directions include this constant offset value; it's computed as an average and stored separately here for data quality purposes (e.g. to identify if/when azimuth value was changed).
4. Available, not applied, heating voltage. Refer to WXT510 user manual for heater operation details.
5. "Approximately" because the PAR sensor is over a decade past its recommended calibration interval. Value should be negative per manufacturer guidelines for usage with millivolt adapter module.
6. The multiplier is calculated as an average to help identify if/when the value was updated.

biofiltro_gps

Raw measurements from the GPS receiver.

Field name	Units	Instruction	Description
TIMESTAMP	TS	-	Machine-formatted timestamp (YYYY-MM-DD hh:mm:ss)
RECORD	RN	-	Sequential record number
UTC_OFFSET	hours	Sample	Clock timezone offset relative to UTC1
latitude_a	degrees	Sample	Degrees latitude (+ = North, - = South)
latitude_b	minutes	Sample	Minutes latitude
longitude_a	degrees	Sample	Degrees longitude (+ = North, - = South)
longitude_b	minutes	Sample	Minutes longitude
speed	m/s	Sample	Speed
course	degrees	Sample	Course over ground
magnetic_variation	degrees	Sample	Magnetic variation from True North (+ = East, - = West)
fix_quality	arb	Sample	GPS fix quality: 0 = Invalid, 1 = GPS, 2 = Differential GPS, 6 = Estimated
nmbr_satellites	count	Sample	Number of satellites used for fix
altitude	m	Sample	Antenna altitude above Earth datum (WSG 84)
pps	ms	Sample	Timing of pulse-per-second (PPS) rising edge, typically 990,000 once synced
dt_since_gprmc	s	Sample	Time since last GPRMC string, normally less than 1 second
gps_ready	arb	Sample	Counts from 0 to 10, with 10 = ready
max_clock_change	ms	Sample	Maximum value the clock was changed in milliseconds
nmbr_clock_change	samples	Sample	Number of times clock was changed

Footnotes:

1. Corresponds to user-defined constant UTC_OFFSET.

biofiltro_wxt

Raw measurements from the weather station.

Field name	Units	Instruction	Description
TIMESTAMP	TS	-	Machine-formatted timestamp (YYYY-MM-DD hh:mm:ss)
RECORD	RN	-	Sequential record number
WXT_AZIMUTH	degrees	Sample	Orientation (azimuth) of weather station relative to True North
WindSpeed	m/s	Sample	Horizontal wind speed
WindDir	degrees	Sample	Horizontal wind direction1
Tmpr	degC	Sample	Ambient air temperature
RH	percent	Sample	Ambient relative humidity
Press	hPa	Sample	Barometric pressure
Rain_amt	mm	Sample	Rain accumulation
Hail_amt	hits/cm^2	Sample	Hail accumulation
HeaterTmpr	degC	Sample	Heater element temperature
HeaterVolts	Vdc	Sample	Heater power source2

Footnotes:

1. Stored wind direction data includes the constant offset value WXT_AZIMUTH.
2. Available, not applied, heating voltage. Refer to WXT510 user manual for heater operation details.

Wiring

Los Gatos Research N₂O/CO/H₂O analyzer

Connect the beige serial cable on the COM3 port of the datalogger to the serial data output port of the N₂O/CO analyzer using a null modem RS-232 cable or standard cable and null modem adapter.

Description	Color	CR1000
serial transmit	brown	C5
serial receive	white	C6
serial ground	yellow	G
shield	clear	G

Los Gatos Research CH₄/CO₂/H₂O analyzer

Connect the black serial cable on the COM2 port of the datalogger to the serial data output port of the CH₄/CO₂ analyzer using a null modem RS-232 cable or standard cable and null modem adapter.

Description	Color	CR1000
serial transmit	brown	C3
serial receive	blue	C4
serial ground	green/yellow	G

WXT510

The data/power cable for the weather station typically stays connected. The table below is provided for reference and is specific to the data cable in the trailer.

Description	Color	M8 conn. pin	CR1000
power input	brown	2	12V
power ground	green	8	G
cable shield	bare	-	G
SDI-12 data Tx	yellow	7	C7
SDI-12 data Rx	black	1	C7
SDI-12 ground	white	3	G
heater (+)	blue	4	SW12†
heater (-)	orange	6	G
not used	red	5	-

†The datalogger disables the heater if input voltage is less than 12.6Vdc to prevent running heaters while on battery power. The WXT510 automatically engages the heater only at predetermined setpoints so it's fine to leave the heater voltage normally enabled.

QUANTUM (PAR) sensor

The QUANTUM (LI-190SA) sensor typically stays connected to the Model 2290 Millivolt Adapter (604Ω), which is wired to a differential analog voltage input channel of the logger. Note wiring is polarity-inverted per manufacturer guidance.

Description	Color	CR1000
Model 2290 Millivolt adapter, negative	blue	DF1 H
Model 2290 Millivolt adapter, positive	green	DF1 L
jumper to CR1000 DF 1L port	green	⏚

GPS receiver

The GPS is hard-wired into serial data port COM1.

Warning: newer GPS receivers may not provide a usable PPS signal without special adapter hardware (see more info here).

Description	Color	CR1000
power input	red	12V
power ground	black	G
power enable	yellow	G
pulse-per-second (PPS)	grey	C1
serial data transmit	white	C2
serial data receive	blue	⏚

Configuration

Los Gatos Research N₂O/CO & CH₄/CO₂ analyzers

Modify both Los Gatos Research analyzers with the following configuration:

• Sampling
  • Rate: 1 Hz
• Serial port
  • Baud rate: 115200
  • Parity: None
  • Stop bits: 1
  • Delimiter (N₂O/CO only): Comma
  • Rate = N (N₂O/CO only): 1 (same as sampling frequency)

WXT510 weather station

Use Vaisala WXT Configuration Tool software to modify settings as follows:

• Device Settings
  • Address: 0
  • Enable heating
  • SDI-12 v1.3, Continuous mode enabled
• Message Settings
  • Wind: Direction average, Speed average
  • PTU: Barometric pressure, Air temperature and Relative humidity
  • Precip: Rain amount and Hail amount
  • Supervisor: Heating temp. and Heating voltage
• Sensor Settings
  • Wind speed unit: m/s
  • Temperature unit: Celsius
  • Barometric pressure unit: hPa
  • Counter reset: Automatic
  • Precip unit: Metric
  • Auto report based on: Rain start/end
  • Direction correction: 0°
  • Averaging time for all sensors: 5 sec
  • Update interval for all sensors: 5 sec

CR1000 data logger

Default configuration values are sufficient, however, users may wish to confirm:

• IP address assignment is either:
  • Set to 0.0.0.0 (for DHCP assignment)
  • Set to the IP reservation described in modem configuration section below
• Appropriate security settings are enabled

Raven RV50 cellular modem

The modem provides an internet connection and***** behaves as the router for the local area network (LAN). Use default network configuration and update security settings to comply with best practices and company guidelines.

(*) the modem presently doesn't have an active data plan, so there's no internet connection but it still serves the important role of DHCP server

Verify the modem issues DHCP IP addresses using the default range values:

• LAN > Ethernet
  • Device IP: 192.168.13.31
  • IP Netmask: 255.255.255.0
  • DHCP Starting IP: 192.168.13.100
  • DHCP Ending IP: 192.168.13.150

Then assign DHCP reservations to ensure devices obtain the same IP address even if the network gets restarted:

Device	IP reservation
Wireless radio	192.168.13.10
CR1000 logger	192.168.13.50
LGR N2O/CO	192.168.13.51
LGR CH4/CO2	192.168.13.52

Picostation M2 wireless radio

The wireless radio provides an access point (AP) so phone or tablet users can connect to the trailer LAN. The wireless users obtain an IP address from the modem and appear on the same subnet as the logger, modem, etc.

• Network
  • Network Mode: Bridge
  • Management IP Address: DHCP
  • DHCP Fallback: 192.168.13.10
• Wireless
  • SSID: WSU Trailer 25012E
  • WPA2-PSK: field_research
  • Channel width: 20 MHz

Licensing

• Original software contributions are licensed under The MIT License.
• Documentation, including images, are licensed under CC-BY-SA-4.0 (Creative Commons Attribution-ShareAlike 4.0 International).
• This work derived from N2O Flux Trailer Weather Station.

References

• Campbell Scientific. CRBasic Program Reference: WindVector. Revision CR1000.Std.32.05.

• Campbell Scientific. HMP45C Temperature and Relative Humidity Probe Instruction Manual. Revision 03/09 Online: https://s.campbellsci.com/documents/us/manuals/hmp45c.pdf

• Campbell Scientific. GPS16X-HVS GPS Receiver Instruction Manual. Revision 9/15. Online: https://s.campbellsci.com/documents/ca/manuals/gps16x-hvs_man.pdf

• Campbell Scientific. WXT510 Weather Transmitter Instruction Manual. Revision 4/07. Online: https://s.campbellsci.com/documents/us/manuals/wxt510.pdf

• LI-COR Biosciences. LI-190SA Quantum Sensor Datasheet. Modified date 2009-11-11T13:32:49. Online: https://www.licor.com/env/pdf/light/190.pdf

• LI-COR Biosciences. Terrestrial Quantum Sensors Instruction Manual. Build date Thursday, May 23, 2019. Online: https://www.licor.com/documents/oo6v1v8bbtoxbd7o299u6a503g32w3g5

• LI-COR Biosciences. Using LI-COR's Millivolt Adapters for Interfacing LI-COR Radiation Sensors to Voltage-reading Dataloggers. Modified 2011-11-04T15:37:35. Online: https://www.licor.com/documents/tnn0vl9t8ukt1y9x26qc

• O'Keeffe, Patrick. N2O Flux Trailer Weather Station. Retrieved 2022-05-24. Online: https://github.com/patricktokeeffe/n2o-trailer-wx

• Vaisala Oyj. Vaisala HUMICAP® Humidity and Temperature Probes User's Guide. Revision 2006. Online: https://www.vaisala.com/sites/default/files/documents/HMP45AD-User-Guide-U274EN.pdf

• Vaisala Oyj. Vaisala Weather Transmitter WXT510 User's Guide. Revision 2006. Online: https://www.vaisala.com/sites/default/files/documents/WXT510_User_Guide_in_English.pdf