Met One 076B Radiation Shield Instruction Manual
- June 10, 2024
- Met One
Table of Contents
Met One 076B Radiation Shield Instruction Manual
www.metone.com
service@metone.com
Copyright Notice
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Technical Support
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Met One Instruments, Inc.
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DESCRIPTION
1.1 The Met One Instruments Power-Aspirated Radiation shield has a large
primary tube for mounting up to four sensors. This tube is surrounded by two
lightweight aluminum cylinder shields designed to thermally isolate the
temperature sensors from the heating effects of the sun. For maximum
reflection of solar radiation, all external surfaces are powder coated with a
gloss white finish. To aid in the circulation of colling air around the outer
shields, an AC powered fan is installed in the top of the aspirator shield.
This fan requires little or no maintenance.
1.2 The 076B has an internal junction box that allows easy field connection
and replacement of sensors without requiring soldering or potting. The
internal junction box minimizes the problems that are associated with the
dirt/moisture/resistance paths between the connections on exposed connectors.
1.3 A single sensor cable (2144) is used for all connections whether relative
humidity, Delta temperature, ambient temperature or combinations of above.
Table 1-1
076B Radiation Shield Specifications
*With two T-200 sensors, an 083 RH cannot be used
INSTALLATION
CAUTION:
To prevent damage to the sensor do not apply pressure or load to the aspirator tube during removal from the shipping tube or carton.
2.1 The Radiation Shield is designed to slide onto a horizontal instrument
mounting boom or support. The mounting arm may be a 191 or 193 crossarm, or
any 3/4″ IPS pipe suitably mounted.
2.2 Slide the top hat onto the tower-mounting and tighten the two Allen screws
on the top of the mount to lock the shield into place.
2.3 Refer to figure 2.1 for sensor installation, and figure 2.2 for standard
sensor wiring. Appendix B details the wiring in the 2144 signal output cable.
Verify the sensor model numbers before installation.
Note: If the Radiation Shield was ordered as part of a system, temperature
and/or relative humidity sensors may have been installed at the factory. If
this is part of a complete system, please refer to the custom wiring diagrams
that were provided with your system as these may differ from the standard
wiring shown in this manual.
2.4 Attach the Radiation Shield to the top hat in quick disconnect box with
the radiation shield inlet facing down and tighten side clamps to fasten.
2.5 Connect AC and sensor cables and route to AC power source and translator
or data logger respectively. Refer to figure 4.1 and Appendix A for power
wiring connections.
2.6 Apply power and verify that aspirator motor is operating.
2.7 Check to see that sensor output is being recorded.
SENSOR INSTALLATION
Figure
2-1 Sensor Installation
STANDARD INTERNAL WIRING
Figure 2-2 Internal Sensor Wiring
TROUBLESHOOTING AND REPAIR
TABLE 3-1 Troubleshooting
REPAIR INFORMATION
A. Electronic repair of the Motor Aspirated Radiation Shield is limited to
replacement of the aspirator motor. If mechanical spare parts are worn or
damaged, please refer to Figure 4-2 and Table 4-1 for a list of replacement
parts.
B. Aspirator Motor Replacement
a. Remove all cables to the shield and remove the entire shield assembly from
tower.
b. Separate shield from quick disconnect box.
c. Unsolder motor wires from receptacle. Note color and pin coding.
d. Remove top hat from shield.
e. Remove fan assembly.
f. Install new fan assembly and secure.
g. Solder motor wires to the proper pins as noted under “c”.
h. Temporarily connect power and verify fan operation.
i. Re-install fan housing assembly to the Radiation Shield.
j. Install assembly on tower and verify correct operation.
Figure 4-1 Internal Fan Wiring Diagram
REPLACEMENT PARTS LIST
Table 4-1 Replacement Parts List
QUALITY ASSURANCE PROCEDURE
5.1 Purpose
To verify correct operation of Model 076B Motor Aspirated Radiation Shield
5.2 Activity
Confirm adequate flow through the radiation shield, and to check the general
condition of the motor aspirated shield. Clean shield for maximum reflectance.
5.3 Frequency
Every 6 months
5.4 Procedure
Place flow monitor, directly below radiation shield and confirm adequate flow.
5.4.1 Hold flow sensor at base of air inlet, position as shown.
5.4.2 With flow sensor in MPH range, the reading should indicate 5.0 or
greater, record value. If flow is below that reading the flow system may be
plugged or the motor is not operating properly.
5.4.3 Clean the top shields, and down tube with a damp rag, to remove any
accumulation of dust and dirt. The white surfaces of the shield should be kept
clean for maximum reflectance of solar radiation.
5.5 Skill level Required
A maintenance technician instructed in the operation of the flow monitor and
disassembly of the 076B Shield.
5.6 Required Information
Record Flow
Record any damage to surface of shield, or down tube.
Figure 5-1 Flow Test of Shield
APPENDIX A
Power Cable (1954) Wiring Diagram
APPENDIX B
Signal Cable (2144) Wiring Diagram
APPENDIX C
Motor Aspirated Radiation Shield
Outline Dimensions
All Dimensions in Inches
References
- Met One - Precision Air Quality Monitoring Instruments
- Met One - Precision Air Quality Monitoring Instruments