Met One Instruments 076B User manual

MODEL 076B
RADIATION SHIELD
OPERATION MANUAL
Met One Instruments, Inc
Corporate Sales & Service: 1600 NW Washington Blvd. Grants Pass, OR 97526
Tel [phone] Fax [phone]
www.metone.com - [e-mail]

076B-9800 Rev B Page 1
076B RADIATION SHIELD
OPERATION MANUAL
1.0 GENERAL INFORMATION
1.1 The Met One Instruments Power-Aspirated Radiation shield consists of a large
primary tube for mounting up to four Model 061 or T-200 sensors; two lightweight
aluminum cylinder shields, painted with a gloss enamel on the outer surfaces for
maximum reflection, and an aspirator motor with fan that requires little or no
maintenance. The Model 061 Ambient Temperature, T-200 Ambient / Delta
Temperature, 083E or 085 Relative Humidity sensors are generally used with shield.
1.2 The 076B has an internal junction box that allows easy field connection 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. The 076B will allow the customer to replace
sensors easily in the field without re-soldering and re-potting.
1.3 A single sensor cable (2144) is used for all connections whether relative humidity,
dew point, Delta temperature, ambient temperature or combinations of above. Refer
to drawing 076B-1.
Table 1-1
076B Radiation Shield Specifications
Radiation Error Less than 0.05 under maximum solar
radiation of 1.6 gm-cal/cm2/min
Power Requirement 115 V 60 Hz @ 1 amp or less
220 V Optional
Temperature -50C to +85C
Weight 5.5 pounds
Sensor Capacity Sensors Mounted
Shield Model 061/T-200 083D
076B-1 1 to 4 1
076B-2 1 to 4 1

076B-9800 Rev B Page 2
2.0 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 horizontally mounted instrument
mounting arm. The mounting arm may be the 5307 mounting arm kit or other ¾ inch
I.P.S. pipe suitably mounted.
2.2 Slide the top hat onto the tower mounting arm tighten the four Allen Screws to lock
into place.
2.3 Attach the Radiation Shield to the top hat in quick disconnect box with the radiation
shield inlet facing down and tighten side clamp to fasten.
2.4 Connect AC and sensor cables and route to AC power source and translator
respectively. Refer to 076B-1 wiring connections.
2.5 Apply power and verify that aspirator motor is operating.
2.6 Check to see that sensor output is being recorded.
3.0 MAINTANCE AND TROUBLE SHOOTING
Table 3-1
076B Troubleshooting Table
Symptom Probable Cause Solution
Fan does not operate Loss of AC power Check AC source
Check all cables
Motor failure Replace fan

076B-9800 Rev B Page 3
3.1 Repair Information
A. Repair of the Power Aspirated Radiation Shield is limited to replacement of the
aspirator motor.
B. Aspirator Motor Replacement
1. Remove all cables to shield and remove entire shield assembly from
tower.
2. Separate shield from quick disconnect box.
3. Unsolder motor wires from receptacle. Note color and pin coding.
4. Remove top hat from shield.
5. Remove fan assembly.
6. Install new fan assembly and secure.
7. Solder motor wires to the proper pins as noted under “C”.
8. Temporarily connect power and verify fan operation.
9. Re-install fan housing assembly to the Radiation Shield.
10. Install assembly on tower and verify correct operation.
Table 2-2
Replaceable Parts List
Motor (120 VAC) 590050
Motor (220 VAC) 590051

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