Met One 061 Air Temperature Sensor Instruction Manual

061 Air Temperature Sensor
Instruction Manual

MODEL 065
TEMPERATURE SENSOR
OPERATION MANUAL

GENERAL INFORMATION

1.1 Model 065 is an air temperature sensor designed to mount in 073B or 5980 Radiation Shields. The temperature sensor is shielded by concentric enameled aluminum plates to reflect solar energy. The shields are designed to greatly reduce errors due to direct solar  radiation and reflected terrestrial radiation. The 073B  and the 5980 are naturally aspirated. The 065 sensor is a precision thermistor unit that produces a resistance charge inversely proportional to temperature.
1.2 Sensor Cable and Connections
Model 065 is supplied with quick disconnect connector. Mating cables are supplied with several types of termination. Refer to cable drawings at end of this manual  for particular wiring.
1.3 Specifications

INSTALLATAION

2.1 Mount the radiation shield on a ¾ inch horizontal pipe. The unit will slide over the end of the pipe and will lock into place with the self- contained Allen head  set screws. The horizontal pipe should be positioned so that the sensor will not be located too close to a potential heat source. Generally it is recommended that the  unit be on the north side of a tower with the sensing unit at least 3 feet from the tower. These sensors are durable, field proven devices; however,
DO NOT DROP OR EXPOSE THE SENSOR TO HEAVY SHOCK!!!
2.2 Wiring Connections
The output of the thermistor sensor has a relatively high resistance that varies inversely with temperature. It is important not to introduce any parallel resistance  paths. A parallel resistance path may be established by a dirt/moisture build-up between two sensor leads. This may occur in poorly made splices and unprotected  connections. It is advisable to always use a protective coating on exposed sensor connections. Use a coating such as clastic rubber (RTV).

2.3 Direct Wiring to a Met One Instruments Translator
When the sensor is connected directly to a Met One Instruments Translator Module the sensor is loaded with the appropriate resistor to provide a linear output.
2.4 Direct Connection to a Data Logger
When the sensor is connected to a data logger; the data logger must have a terminating resistor to provide a linear output. Refer to Figure 2-1.

OPERATIONAL CHECK-OUT AND CALIBRATION

3.1 Temperature Sensor Check-out
Compare sensor readings against a precision mercury thermometer or other temperature standard. Use either connected logger, translator Module or Ohmmeter to measure and compare readings of temperature vs. resistance.

MAINTENANCE AND TROUBLESHOOTING

**4.1 General Maintenance Schedule***

6 – 12 Month Intervals:
A. Inspect sensor for proper operation per Section 3.1.
*Schedule is based on average to adverse environments.
4.2 Troubleshooting Procedures
Incorrect sensor signal: check sensor input connections; check temperature vs. sensor output signal using Table 3-1. Verify that the sensor has the correct terminating resistor if not used with a Met One Instruments Translator.
4.3 Temperature Sensor Calibration
The sensors are tested for calibration conformity at the factory. It is not possible to make alterations to the sensor’s calibration, as it is fixed.
4.4 Calibration Verification
Install the 065 inside of a Styrofoam container (ice chest) and push a glass thermometer into the container. With the top on the container and no air leaks it is possible to verify the operation of the sensor ±0.5°C within 30 to 60 minutes.

Table 3-1A
Model 065 RESISTANCE CHART

*VALUE WITH 18.7K RESISTOR IN PARALLEL WITH SENSOR
RANGE –30°C TO +50°C
THERMISTOR BEAD 44203
Table 3-1A

Table 3-1B
Model 065 RESISTANCE CHART

Table 3-1B

Table 3-1B
Model 065 RESISTANCE CHART Continued

VALUE WITH 18.7K RESISTOR IN PARALLEL WITH SENSOR
RANGE -22˚F TO +122˚F
TERMISTOR BEAD 44203
Tc= -(R18700/(18700+R)-12175)/127.096
Rt = -(127.096Tc-12175)18700/(127.096*Tc-12175+18700)
Table 3-1B
065-9800 Rev C
Corporate Sales & Service: 1600 NW Washington Blvd. Grants Pass, OR 97526
Tel 541-471-7111 Fax 541-471-7116
www.metone.com – service@metone.com

References

• Met One - Precision Air Quality Monitoring Instruments
• Met One - Precision Air Quality Monitoring Instruments

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