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INSTRUCTION MANUAL
61302V
Barometric Pressure Sensor
September 2009
Copyright © 2009
Campbell Scientific (Canada)Corp.
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WARRANTY AND ASSISTANCE
This equipment is warranted by CAMPBELL SCIENTIFIC (CANADA) CORP. (“CSC”) to
be free from defects in materials and workmanship under normal use and service for
twelve (12) months from date of shipment unless specified otherwise. ***** Batteries
are not warranted. ***** CSC's obligation under this warranty is limited to repairing or
replacing (at CSC's option) defective products. The customer shall assume all costs of
removing, reinstalling, and shipping defective products to CSC. CSC will return such
products by surface carrier prepaid. This warranty shall not apply to any CSC products
which have been subjected to modification, misuse, neglect, accidents of nature, or
shipping damage. This warranty is in lieu of all other warranties, expressed or implied,
including warranties of merchantability or fitness for a particular purpose. CSC is not
liable for special, indirect, incidental, or consequential damages.
Products may not be returned without prior authorization. To obtain a Return
Merchandise Authorization (RMA), contact CAMPBELL SCIENTIFIC (CANADA) CORP.,
at (780) 454-2505. An RMA number will be issued in order to facilitate Repair Personnel
in identifying an instrument upon arrival. Please write this number clearly on the outside
of the shipping container. Include description of symptoms and all pertinent details.
CAMPBELL SCIENTIFIC (CANADA) CORP. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a purchase order to
cover repair costs.
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61302V Barometric Pressure Sensor
Table of Contents
1. INTRODUCTION..............................................................................2
2. SPECIFICATIONS............................................................................2
3. INSTALLATION................................................................................3
3.1. Mounting........................................................................................... 3
3.2. Wiring........................................................................................ 3
3.2.1. Serial Output Wiring.............................................................. 4
3.2.2. Analog Output Wiring............................................................ 4
4. SENSOR OPERATION .................................................................... 4
4.1. Serial Output............................................................................. 5
4.2. Analog Output........................................................................... 6
4.3. Software Commands ................................................................ 7
5. PROGRAMMING.............................................................................. 8
5.1. Serial Output Program Example ...............................................9
5.2. Voltage Output Program Example .......................................... 11
Appendix A
Typical Wiring Connections...................................................................13
Appendix B
Software Configuration for Voltage Output.............................................14
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61302V Barometric Pressure Sensor
1. INTRODUCTION
MODEL 61302V Barometric Pressure Sensor is a versatile
electronic barometer featuring high accuracy, low power, wide
operating temperature range, and RS-232 serial data I/O or a
calibrated voltage output.
Low power consumption and wide temperature range make the
61302V ideal for remote applications using battery or solar power.
An accuracy of ±0.3 hPa rms is maintained over the entire
specified operating pressure and temperature range. Full scale
voltage output (2.5V or 5V) may be set to span any portion of the
500 to 1100 hPa operating range. RS-232 serial I/O options
include continuous or polled ASCII text output or NMEA marine
output. The sensor is supplied with the following standard
configuration:
• RS232 serial output (TTL levels)
• Polled mode, 9600 baud ( 8 bit/1 stop bit/no parity)
• Measurement range = 500 to 1100 hPa (10 samples
averaged, Output when polled)
2. SPECIFICATIONS
Pressure: 500 to 1100 hPa standard range
Accuracy: ±0.2 hPa rms at 25°C, ±0.3 hPa rms over
-50 to +60°C (serial output)
Resolution: 0.01 hPa (serial output)
0.15 full scale (Analog output)
Operating Range: -50°C to +60°C (unit must remain dry)
Output Rate: 1.8 Hz (max) to 1 per minute (software
selectable)
Voltage Output: 0 to 5000 mV (standard), optional 0 to 2500
mV
12-bit resolution (1 in 4000)
Selectable pressure range - 500 to 1100
hPa (standard)
Resolution is dependent on selected
pressure range
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Serial Output: Full duplex RS-232 (standard & TTL levels)
1200 to 38400 baud
Continuous ASCII text, polled ASCII text,
NMEA
Supply Voltage: 7 to 30 VDC
2.8 mA with Vout
1.4 uA shutdown (Trig=0V)
7 mA with serial I/O (standard)
Case: Fiber-reinforced thermoplastic
Weight: Net 0.2 lb, Shipping 1 lb
3. INSTALLATION
3.1. Mounting
The sensor must be protected from the elements either by being
placed in a weather proof enclosure or indoors. The 61302V has
two mounting holes that are spaced 1” on centre. The screws and
grommets shipped with the sensor will aid in mounting the sensor
inside one of Campbell Scientifics’ white fibreglass enclosures. If
the 61302V is to being installed in an enclosure a QDP HYDRO
VENT should used. Otherwise the included poly tube can be used
to vent the sensor to the outdoors via the enclosure port. Vent
this tube about 1” out the cable entry port and insert one of the
white hydrophobic filters (provided) into the end of the tube.
3.2. Wiring
The recommended measurement method is using the serial
“COM” channels available on a datalogger (CR3000, CR1000,
CR800 series). When necessary the sensor can be reconfigured
to output a voltage signal, which can be measured on the analog
channels of a datalogger. This reconfiguration is addressed in
Section 4.2 and Appendix B.
The recommended power supply for the sensor is the switched
12V channel. This will help conserve station power.
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3.2.1. Serial Output Wiring
Colour Sensor Designation
White Tx COMn* Rx
Blue Rx COMn* Tx
Green Reference G
Red +PWR SW12V (recommended) or 12V
Black -PWR G
Clear Shield G
*The “n” indicates the COM port number
As shown in the above table, the serial wiring requires a crossover
between the sensor transmit/receive and the datalogger
transmit/receive.
3.2.2. Analog Output Wiring
Datalogger Terminal (CR800/850,
CR1000, CR3000)
Colour
Sensor
Designation
Datalogger Terminal (CR800/850,
CR1000, CR3000, CR23X)
Datalogger Terminal
(CR10X, CR510)
White Vout Single Ended Channel Single Ended Channel
Blue Optional Trigger No Connection or SW12V
Green Reference
No Connection or
SW12V
AG
Red +PWR SW12V or 12V SW12V or 12V
Black -PWR
Clear Shield
Jumper b/w Ctrl Port &
SW12 CTRL
AG
G
Single ended wiring is the only available analog measurement.
4. SENSOR OPERATION
The 61302V Barometric Pressure sensor offers a variety of serial
and analog configurations, which are discussed in the following
sections. Communication/Output connections are made with the
5-position terminal plug included with the sensor. Changes to the
sensor configuration require changes to jumper and/or software
settings. Access the jumpers by loosening the two screws in the
sensor enclosure and removing the cover. See Appendix A for
wiring details and jumper settings.
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If changed from the standard configuration to an analog output,
please note that the software Vout Scale parameter must be set to
agree with the hardware Voltage Output Scale jumper (P3) in
order to achieve calibrated output.
4.1. Serial Output
Hardware jumper settings and software parameters determine the
RS-232 serial communication format. The Appendix A Wiring
Diagram shows jumper locations and function.
P1 A/B/C sets output format, baud rate, output rate, and
averaging. The table below summarizes P1 configurations.
P3 A/B sets the RS-232 hardware function. AUTO (AA) enables
RS-232 hardware when valid standard RS-232 signals are present
at RX and TX. When not present, the RS-232 hardware is
disabled to save power. FIXED (AB) enables RS-232 hardware at
all times so it can be used with TTL RS-232 signal levels.
P4 A/B configures the terminal connections for RS-232. Both
jumpers must be in position A for RS-232 serial communication.
Format Description
Continuous ASCII
Text
Polled ASCII Text
Marine NMEA
Note that NMEA output is normally specified to work on RS-422
and RS-485 networks. The NMEA output here conforms to the
standard data format but the electrical connection uses RS-232
signal levels.
In POLLED ASCII mode, the unit sends data only after receiving a
poll command. The poll command is Ma! where ‘a’ is the sensor
address value. The standard address is ‘0’ (ASCII 48) for a poll
command of M0! Please see Section 4.3 for details on changing
the polling address. Standard baud rate is 9600 but any of
several available baud rates between 1200 and 38400 may be
used.
(standard)
4800 baud
Software
9600 baud
10 sample average
1.8 Hz output
9600 baud
10 sample average
Output when polled
10 sample average
1Hz output
Output parameters determined by
software settings
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4.2. Analog Output
If the 61302V is to be used in a voltage output mode it is
recommended that the output range of the sensor be remapped
by changing the output range in the sensor software. This is
important in maintaining the highest level of measurement
accuracy. Hardware jumpers and software parameters determine
voltage output operation. Appendix A shows jumper
configurations, and Appendix B shows steps for software
configuration. The jumper settings are also described below.
Both P4 jumpers must be in position B for voltage output.
Jumper P3 sets the Voltage Output Scale to either 0-5000 mV or
0-2500 mV.
Note - Jumper P3 must agree with the software Vout Scale
parameter in order to achieve calibrated output.
The voltage output scale may be mapped to any part of the 500 to
1100 hPa pressure range using the VOUT HI and VOUT LO
software parameters. The standard setting maps 0 to 5000 mV
with 500 to 1100 hPa.
For example:
hPa = 0.12 * mV + 500
Effective range is 600 hPa, Analog signal resolution is 12
bit (resolution = 600/2
Therefore the effective resolution is about 0.15 hPa
Better effective resolution may be achieved by mapping the
voltage output to a narrower range of pressure with the VOUT HI
and VOUT LO parameters. In most applications VOUT LO can be
set to 950 hPa and VOUT HI can be set to 1050 hPa (VOUT
Scale set to 0-5000 mV):
hPa = 0.02 * mV + 950
Effective range is 100 hPa, Analog signal resolution is 12
bit (resolution = 100/2
Effective resolution is about 0.025 hPa
Please see Section 4.3 and Appendix B for details on changing
the VOUT HI and LO parameters.
With jumper P4 configured for voltage output, a special optional
trigger (TRIG) input may be used to control barometer power.
When TRIG=0V, all processes cease and power consumption is
reduced to 1.4uA. When the voltage on TRIG > 1.8V (or left
floating), normal operation resumes with a power up reset. The
TRIG input connection is optional. It is recommended to connect
12
)
12
)
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the TRIG to +PWR or left floating, as the datalogger program will
control the sensor power.
4.3. Software Commands
Software commands sent via serial communication may be used
to set operational parameters. The sensor must be configured for
serial communication and connected to a PC or other compatible
device using a program like HyperTerminal.
New settings are stored in temporary memory and must be
burned to flash with command CMD420 to be retained.
Note that the P1 jumper must be configured for SOFTWARE
format to alter baud rate, sample average count, and output rate
parameters. Although the sensor may receive commands at any
time, measurement output may be caused by sending three ESC
(ASCII 27) characters or CMD300 1. While paused, COMMAND
mode is indicated by a “>” prompt. All commands must be
terminated with a carriage return CR (ASCII 13).
Use “?” to list available commands as shown below.
>?
YOUNG 61300 SERIES BAROMETER V2.03
---------------------------------------CMD100 n OUTPUT PERIOD (0-60 sec)
CMD105 n AVG SAMPLE COUNT (0-32)
CMD110 n OUTPUT FORMAT (1=ASCII 2=POLLED 3=NMEA
4=RAW 5=DIAG)
CMD120 n MULTIPLIER (10000 = 1.0000)
CMD125 n OFFSET (hPa x 100)
CMD130 n SEA LEVEL CORRECTION (hPa x 100)
CMD140 n VOUT RANGE HI (500-1100)
CMD142 n VOUT RANGE LO (500-1100)
CMD144 n VOUT SCALE (2=2.5V 5=5V)
CMD150 c POLL ADDR CHAR
CMD160 n BAUD RATE (38400,9600,4800,2400,1200)
CMD300 n 1=STOP, 2=RUN
CMD310 n FORCE VOUT (0-5000 FULL SCALE)
CMD400 n 1=RPT TEXT, 2=RPT CODE ONLY
CMD410 GET CAL TABLE
CMD420 STORE SETUP PARAMETERS
>
CMD100 n sets output period in seconds. When set to zero, the
output rate is about 1.8 per second.
CMD105 n sets the average sample count. Higher sample count
yields more stable readings but will lengthen the startup delay.
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CMD110 n sets output format. RAW and DIAG settings are for
factory use only.
CMD120 n sets the output multiplier. 10000 represents 1.0000
CMD125 n sets the output offset in hPa x 100
CMD130 n sets the sea level correction in hPa x 100
=[Punadjust *( Mult / 10000)] + [(Offset /100) + (Correction Sea Lvl
/ 100)]
CMD140 n sets the Vout Pressure Range HI
CMD142 n sets the Vout Pressure Range LO Vout Pressure
Range HI must be greater than Vout Pressure Range LO
CMD144 n sets the Vout Scale. 2 = 0 to 2500 mV. 5 = 0 to 5000
mV. This parameter setting must agree with the physical P3
jumper position to achieve calibrated voltage output.
CMD150 c sets the poll address character. Any ASCII character
from ‘0’ (ASCII 48) to ‘z’ (ASCII 122) may be used.
CMD160 n sets the baud rate. Acceptable values are 38400,
9600, 4800, 2400, and 1200. Note that the baud rate change
occurs immediately after the command is received. Therefore, in
order to continue communicating, the serial communication
program that issued the command must also change to match.
CMD300 n causes the sensor to pause or resume measurement.
1 = Stop, 2 = Run.
CMD400 n causes the sensor to issue a report summarizing
parameter settings.
1 = RPT text
2 = RPT code only
CMD410 retrieves the internal calibration table. This is
for factory use only.
CMD420 burns new parameter settings to flash memory. This
step must take place to retain changes otherwise parameters will
revert to the previous values at the next power up.
5. PROGRAMMING
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The 61302V draws upwards of 7mA of power when activated.
Depending on your power supply it may be beneficial to conserve
power. This can be achieved by powering the sensors on and off.
This is done through the switched 12V port on the CR10X,
CR23X, CR800, CR850, CR1000, and CR3000. This is used in
the following program examples.
The default measurement units are Hectopascals (hPa). The
units can be converted by adding programming which makes use
of the following conversions.
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Multipliers to convert the hPa reading to different units
The weather service and most airports correct the pressure
reading at a particular station to what it would be if that station
were located at sea level. This is done so that weather forecasters
can obtain a clearer picture of what is happening in the
atmosphere.
The following equation is used in the program examples to
determine the pressure correction factor. This can then be added
to the measured value. Because barometric pressure is greatly
affected by elevation, the elevation of the site used in the equation
should be as accurate as possible. Where Elevation is in meters
above sea level.
P = 1013.25 [ 1 – ( 1 – Elevation/44307.69231 ) ^5.253283 ]
For Multiply by
kPa 0.1
Mm of Hg 0.75006
In of Hg 0.02953
mBar 1.0
PSI 0.0145
5.1. Serial Output Program Example
The program example illustrates the polling of a 61302V in its
default configuration using a CR1000 datalogger.
Communications will occur on serial port COM1. The sensor is
powered for one minute before the top of each hour, at which time
the sensor is polled for a measurement. The program also
includes the option to correct for elevation. The measurement
units in the example are hPa.
'CR1000 Series Datalogger
' Jumper P1 will need to be set to Polled mode (jumpers B & C in place)
' Jumper P3 will need to be set to "Fixed" modes (as per Appendix A)
' Jumper P4 will need to be set to Serial mode (A position)
' Baud 9600, 8 bit, 1 stop, no parity.
'61302V Wiring
'Red - CR1000 SW12V (Unit can be powered continuously if power consumption is not an
issue)
'Black - CR1000 G
'Blue - CR1000 C1 (Tx)
'White - CR1000 C2 (Rx)
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'Green - CR1000 G
'Shield - CR1000 G
'Declare Public Variables
Public BP_Poll As String, CR As String
Public BP_raw As String
Public BP_string As String
Public Elevation_Correction
Public BP_61302V As Float 'Default units are hPa
'Declare Constants
Const Elevation = 0 'This value must be added in order to correct for elevation (meters).
'Define Data Tables
DataTable (Hourly,1,-1)
DataInterval (0,1,Hr,10)
Sample (1,BP_61302V,IEEE4)
EndTable
'Main Program
BeginProg
'*** 61302V Sensor Polling Variables ***
BP_Poll = "M0!"
CR = CHR(13)
'Configure ComPort 1 for use with the 61302V
SerialOpen (Com1,9600,0,0,1000)
Scan (5,Sec,0,0)
' Switch 61302V Sensor On 1 minute before the top of the hour
If TimeIntoInterval (59,60,Min) Then SW12 (1)
' Poll 61302V Sensor at the top of the hour
If TimeIntoInterval (0,60,Min) Then
SerialFlush (Com1) 'Clear buffer before polling for a new measurement
SerialOut (Com1,BP_Poll,"",0,100) 'Send sensor poll command
SerialIn (BP_raw,Com1,100,CR,100) 'Receive sensor response
SplitStr (BP_string,BP_raw,"",1,0) 'Parse out BP value
BP_61302V = BP_string 'Convert ASCII to numeric value
' Switch 61302V Sensor Off after polling
SW12 (0)
' Correct Barometric Pressure value for elevation above sea level (elevation must be in
meters)
Elevation_Correction = 1013.25 * (1 - (1 - Elevation/44307.69231)^5.253283)
BP_61302V = BP_61302V + Elevation_Correction
EndIf
CallTable Hourly
NextScan
EndProg
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5.2.
Voltage Output Program Example
The program example illustrates the analog measurement of a
61302V in the configuration shown in Appendix A, using a
CR1000 datalogger. The sensor is powered for one minute before
the top of each hour, at which time the sensor is polled for a
measurement. The program also includes the option to correct for
elevation. The measurement units in the example are hPa.
'CR1000 Series Datalogger
'61302V will need to have the following configuration:
' Jumper P1 will need to be set to Continuous ASCII mode (jumpers A, B, & C in place)
' Jumper P3 will need to be set to "5VDC" mode (A position)
' Jumper P4 will need to be set to Voltage mode (B position)
'61302V Wiring
'Red - CR1000 12V (power continuously for testing)
'Black - CR1000 AG
'White - CR1000 SE1
'Blue - No Connection
'Green - CR1000 AG
'Shield - CR1000 AG
'Declare Public Variables
Public BP_61302V_Analog
Public Elevation_Correction
'Declare Constants
Const Elevation = 0 'This value must be added in order to correct for elevation (meters).
'Define Data Tables
DataTable (Hourly,1,-1)
DataInterval (0,60,min,10)
Sample (1,BP_61302V_Analog,IEEE4)
EndTable
'Main Program
BeginProg
Scan (5,Sec,0,0)
' Switch 61302V Sensor On 1 minute before the top of the hour
If TimeIntoInterval (59,60,Min) Then SW12 (1)
' Poll 61302V Sensor at the top of the hour
If TimeIntoInterval (0,60,Min) Then
'*** Measure Analog 61302V ***
VoltSe (BP_61302V_Analog,1,mV5000,1,1,0,_60Hz,0.12,500)
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' Switch 61302V Sensor Off after polling
SW12 (0)
' Correct Barometric Pressure value for elevation above sea level (elevation must be in
meters)
Elevation_Correction = 1013.25 * (1 - (1 - Elevation/44307.69231)^5.253283)
BP_61302V_Analog = BP_61302V_Analog + Elevation_Correction
EndIf
CallTable Hourly
NextScan
EndProg
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Appendix B
Software Configuration for Voltage Output
Listed below are the steps to remap the measurement range of the
61302V.
NOTES:
• Before making any jumper changes be sure that power is disconnected
and that you and your work area are free of static discharge potential.
• The following example assumes that the 0-5V output range will be used.
If you require the 0-2.5V output range you will need to change this
software configuration as well. This can be done with CMD144.
• All commands must be completed with hitting the ENTER key.
1. Connect the 61302V to the PC. Please note in order to make the
connection to the PC you will require either an interface board (i.e.
DB9M-TERM), or a 9-pin cable with connections for Tx, Rx, and Ground.
The sensor must have P1 configured for SOFTWARE mode (no
jumpers), and P4 must have both jumpers in position A.
2. Start a HyperTerminal session with the following port settings of 9600
baud, 8 bit, 1 stop bit, no parity.
3. Power the sensor up. The sensor should start outputting measurements.
Interrupt the output by pressing the Esc key three times, which will give
you command prompt (>). Entering a question mark will give you a list of
the available commands. Please note that the syntax is case sensitive,
and any typing error will require that you reenter the command.
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4. Use CMD140 to set the upper measurement limit to 1050. Use CMD
142 to set the lower measurement limit to 950. These changes must be
saved to flash memory, which is done by entering CMD420.
5. Confirm that the changes have been saved to memory by entering
CMD400 1. This will provide a list of all parameters in flash memory.
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6. Restart the measurement process with CMD300 2.
7. Once the configuration is complete you can power the sensor down and
replace all jumpers required for your specific application.
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