Met One Instruments 083F User manual

083F-9800 Rev A
Met One Instruments, Inc
Corporate Sales & Service: 1600 NW Washington Blvd. Grants Pass, OR 97526
Tel [phone] Fax [phone]
www.metone.com - [e-mail]
MODEL 083F
RELATIVE HUMIDITY SENSOR
MANUAL

083F-9800 Rev A
Page 2

083F-9800 Rev A
Page 3
Copyright Notice
Model 083F Relative Humidity Sensor Manual.
© Copyright 2021 Met One Instruments, Inc. All Rights Reserved Worldwide. No part of
this publication may be reproduced, transmitted, transcribed, stored in a retrieval
system, or translated into any other language in any form by any means without the
express written permission of Met One Instruments, Inc.
Technical Support
Should you require support, please consult your printed documentation or our website
www.metone.com to resolve your problem. If you are still experiencing difficulty, you
may contact a Technical Service representative during normal business hours;
Monday – Friday 7:00 a.m. to 4:00 p.m. Pacific Time.
Voice: [phone]
Fax: [phone]
E-Mail: [e-mail]
Mail: Technical Services Department
Met One Instruments, Inc.
1600 NW Washington Blvd.
Grants Pass, OR 97526

083F-9800 Rev A
Page 4
Safety Notice
The contents of this manual have been checked against the hardware and software
described herein. Since deviations cannot be prevented entirely, we cannot guarantee
full agreement. However, the data in this manual is reviewed regularly and any
necessary corrections included in subsequent editions.
Faultless and safe operation of the product presupposes proper transportation, storage,
and installation as well as careful operation and maintenance. The seller of this
equipment cannot foresee all possible modes of operation in which the user may
attempt to utilize this instrumentation. The user assumes all liability associated with the
use of this instrumentation. The seller further disclaims any responsibility for
consequential damages.
Warranty
Products manufactured by Met One Instruments, Inc. are warranted against defects in
materials and workmanship for a period of (1) year from the date of shipment from the
factory. Offered products not manufactured by Met One Instruments, Inc. will be
warranted to the extent and in the manner warranted by the manufacturer of that
product.
Any product found to be defective during the warranty period will, at the expense of Met
One Instruments, Inc. be replaced or repaired and return freight prepaid. In no case
shall the liability of Met One Instruments, Inc. exceed the purchase price of the product.
This warranty may not apply to products that have been subject to misuse, negligence,
accident, acts of nature or that have or modified other than by Met One Instruments,
Inc. Consumable items such as bearings are not covered under this warranty.
Other than the warranty set forth herein, there shall be no other warranties, whether
expressed, implied or statutory, including warranties of fitness or merchantability.

083F-9800 Rev A
Page 5
Table of Contents
1. GENERAL INFORMATION .................................................................................... 6
1.1. Description ........................................................................................................................... 6
1.2. 083F Options ........................................................................................................................ 8
1.2.1. Radiation Shield Compatibility Option: ............................................................................ 8
2. SENSOR SITING .................................................................................................... 8
3. INSTALLATION ...................................................................................................... 9
3.1. Mounting Instructions ............................................................................................................ 9
3.2. Wiring Instructions .............................................................................................................. 10
4. OPERATIONAL CHECK-OUT AND CALIBRATION ........................................... 11
4.1. Relative Humidity Sensor Check-out ................................................................................... 11
4.2. Limitations of RH Measurements at Below Freezing Temperatures ..................................... 11
4.3. General Maintenance Schedule .......................................................................................... 12
4.4. 083F Relative Humidity Sensor Maintenance and Calibration .............................................. 12
4.5. Sensor Maintenance ........................................................................................................... 12
4.5.1. Sensor Element ............................................................................................................ 12
4.5.2. Spare Parts .................................................................................................................. 13
5. Operational Specifications ................................................................................. 14

083F-9800 Rev A
Page 6
1. GENERAL INFORMATION
1.1. Description
The 083F sensor is an extremely accurate microprocessor controlled relative humidity
sensor. The relative humidity sensor responds to the full range of 0 to 100% humidity.
Response is linear with negligible hysteresis or temperature dependence. The sensor
is designed to be mounted in a radiation shield when used outdoors. The exact model
number you order will determine the functions of your sensor. The following section
describes the model number feature assignments.
Figure 1 Model 083F-0-35 Sensor

083F-9800 Rev A
Page 7
Figure 2 Model 083F-0-6 Sensor

083F-9800 Rev A
Page 8
1.2. 083F Options
The 083F options are defined by dash numbers as follows:
083F-0-__ (Shield Option)
1.2.1. Radiation Shield Compatibility Option:
6 = Use with Model 076B motor aspirated radiation shield. This sensor comes with 8-
inch long pigtail wires for connection to the radiation shield junction box. Refer to the
radiation shield manual for sensor and cable connections.
35 = Use with Model 074 naturally aspirated radiation shield. This sensor has a circular
connector for use with Met One Instruments cable PN 2348.
2. SENSOR SITING
The EPA recommends sensor mounting in a radiation shield at a 2 meter height, ideally
over green mowed grass to minimize related terrestrial radiation errors on the readings.
Typical installations may vary significantly from these recommendations due to
geographic limitations or specific monitoring requirements.

083F-9800 Rev A
Page 9
3. INSTALLATION
If the sensor is to be mounted in a radiation shield, refer to the radiation shield manual
section for mounting details. Typical installations are shown below.
Sensors not installed in a radiation shield should be mounted in a representative
location having good airflow and shaded from sunlight or other heat radiation sources
that would affect measurement of relative humidity.
3.1. Mounting Instructions
Figure 2 Radiation Shield Installation
REMOVE CLIPS FROM
INNER TUBE USING
LONG NEEDLE NOSE
PLIERS. PLACE
SENSOR IN CLIPS AND
REINSTALL. PUSH
SENSOR INTO INNER
TUBE AS DEEP AS
POSSIBLE WITHOUT
TOUCHING BOTTOM
PLATE
SENSOR WIRE
CONNECTIONS IN
J-BOX:
TERMINAL WIRE
7 GRN
8 YEL/ORG
9 WHT
INSTALL SENSOR INTO
TRIANGULAR MOUNTING
ADAPTER AND ATTACH
ADAPTER PLATE TO
SHIELD
SLIDE SENSOR INTO
THE SHIELD UNTIL THE
TOP TOUCHES THE
PLATE. BACK OUT
ABOUT ½” AND SECURE
THE SENSOR TO THE
MOUNTING ADAPTER
BY TIGHTENING THE
TWO SET SCREWS
WITH SUPPLIED 5/64”
ALLEN WRENCH.

083F-9800 Rev A
Page 10
3.2. Wiring Instructions
Sensor Connection Wire Color Description
Pin A White +10 to +18 VDC
Pin B Green Signal Ground
Pin C Yellow or Orange RH Analog Output
Pin D Black No Connection
Pin E Red No Connection
Pin F No Connection No Connection
No Connection White/Brown Shield
Figure 3 Electrical Connector
View looking at connector pins. (Pins are also identified on connector).

083F-9800 Rev A
Page 11
4. OPERATIONAL CHECK-OUT AND CALIBRATION
4.1. Relative Humidity Sensor Check-out
To verify correct wiring and test the basic sensor operation, blow on the sensor. The
moisture in your breath should cause the relative humidity reading to rise.
The relative humidity sensor has been calibrated at the factory. To check for proper
operation of the sensor it is advised that the output signal be checked against a local
weather service facility or a local relative humidity measuring device such as a
psychrometer. Due to normal atmospheric and geographical variations, the local
weather service data should be used only as a guideline. Ambient air relative humidity
can be expected to vary significantly over short distances and in brief periods of time.
4.2. Limitations of RH Measurements at Below Freezing Temperatures
The sensor’s relative humidity output is referenced to saturated water vapor pressure
above liquid water. When the air temperature is below freezing, the sensor’s maximum
theoretical measurement range is limited as follows:
Air Temperature
(Deg C)
Maximum RH
(%)
0 100
-5 96
-10 92
-15 88
-20 84
-25 80
-30 76
-35 72
-40 68
-45 64
-50 60

083F-9800 Rev A
Page 12
MAINTENANCE AND TROUBLE SHOOTING
4.3. General Maintenance Schedule
6 – 12 Month Intervals:
Inspect the sensor for proper operation per Section 4.0.
12 Month Interval:
Return the sensor to Met One Instruments for calibration.
Replace the two 720050 O-Rings.
Replace the 860014 Filter Membrane.
4.4. 083F Relative Humidity Sensor Maintenance and Calibration
WARNING: The sensor can be incorrectly calibrated or permanently damaged through
improper acts. Do not attempt a repair or calibration if you are unsure of the procedure.
Do not touch the sensor element if you do not know the correct procedure.
The instrument should operate for an extended period of time with a minimum of care or
maintenance.
The sensor should be re-calibrated every 12 months.
If parts or maintenance assistance are required, contact Met One Instruments. Obtain
shipping instructions and a return authorization (RA) before returning any unit.
4.5. Sensor Maintenance
4.5.1. Sensor Element
The RH sensor element is not user-replaceable (replacement requires sensor
recalibration). If the element becomes damaged please send the 083F sensor to Met
One Instruments for repair. Please obtain shipping instructions and a return
authorization (RA) number before returning any unit.
Met One Instruments manufactures an RH Calibration Kit part number 10233 which can
be purchased to perform a calibration after the sensor element is replaced. Please
contact the Met One Service Department to purchase the calibration kit.

083F-9800 Rev A
Page 13
4.5.2. Spare Parts
Figure 5 Spare Parts
820216 RH SENSOR ELEMENT (Requires factory calibration)
560014 FILTER, MEMBRANE
720050 O-RING (Two required)
560014
820216
720050

083F-9800 Rev A
Page 14
5. Operational Specifications
Model Number: 083F
Relative Humidity
RH Sensing Element: Thin film polymer capacitor
Range: 0 to 100% RH
Accuracy: ± 2.0% from 0 to100% RH
Response Time: 10 sec. with 2 m/s aspiration
Temperature:
Temperature Operation Range: -50° C to +50° C (-58° F to 122° F)
Temperature Coefficient: Compensated internally
Analog Output: 0 to 1 VDC
AutoMet Auto ID: No
General
Input Power: 10 to 18 VDC @ < 5 mA
Dimensions: Length: 8.5 in (21.59 cm)
Diameter: 0.75 in (1.91 cm)