Notes:
Connect only the Outputs desired. See the HX80 Manual for details.
Do not apply DC Power until all wiring is completed.
2
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TABLE OF CONTENTS Page
1.0 Quick Startup 1
List of Illustrations 4
List of Tables 4
2.0 Introduction 5
2.1 General Description 5
2.2 Specifications Summary 6
2.3 Model Descriptions 7
2.4 Available Options 7
3.0 Installation 9
3.1 Mounting the Probe 9
3.2 Mounting the Electronics Unit 10
3.3 Electrical Wiring 10
3.3.1 Probe Only 10
3.3.2 Probe with Electronics 11
4.0 Basic Block Diagram 14
4.1 Probe Assembly 14
4.2 Electronics Module 15
4.3 Complete System 15
5.0 Operation 17
5.1 Initial Bench Testing 17
5.2 Normal Operation 17
5.3 Factory Default Conditions 17
5.4 RS-232 Serial Port 19
5.4.1 Serial Port Setup 19
5.4.2 Changing the Digital Display 19
5.4.3 Changing the Output Ranges 20
5.4.4 Programming the Alarm Relays 21
5.4.5 Calibrating the Analog Outputs 22
6.0 Maintenance 23
6.1 Sensor Circuit Board 23
6.1.1 Replacing the Sensor Board 23
6.1.2 Removing Components 23
6.1.3 Sensor Reassembly 24
7.0 Specifications 25
3
Page 6
LIST OF ILLUSTRATIONS Page
2-1 Some HX80 Configurations 5
3-1 System with Sample Cell 9
3-2 Installing the Mounting Lugs 10
3-3 Probe Wiring Diagram 11
3-4 Electronics Unit Wiring 13
4-1 Probe Block Diagram 14
4-2 System Block Diagram 16
6-1 Removing Retaining Ring 23
6-2 Sensor Exploded View 24
LIST OF TABLES Page
2-1 Standard Configurations 7
2-2 Measurement Ranges 8
3-1 Probe Wiring 11
3-2 Electronics Wiring 12
3-3 Serial Port Wiring 12
5-1 Standard Output Scaling 18
4
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2.0 INTRODUCTION
2.1 GENERAL DESCRIPTION
The HX80 Series is a family of humidity probes and electronic modules that offer a
variety of measurement parameters with high accuracy. In addition to Percent Relative
Humidity (%RH), probes are available to also measure Temperature and Pressure.
Electrical analog and digital outputs are provided for not only these measured
parameters, but may be provided for microprocessor- computed parameters as well.
These include parts-per-million by volume (ppmv), parts-per-million by weight (ppmw),
grains of water per pound of dry gas (gr/lb), and others.
The HX80 system is designed for ease of installation and operation. Field-replaceable
sensor modules have standardized outputs for interchangeability without recalibration.
The power requirement is a common unregulated DC power supply. User-available
electrical outputs include linear analog voltage (or optional current), a digital bidirectional serial port, and alarm relays. Mounting options include Wall Mount, Remote
Mount, and Duct Mount configurations. Additional options include high temperature and
high pressure probes. A remote or local Display Unit (Type DIS) is available, with a
two-line LCD display, alarm relays, and three 4 to 20 mA electrical outputs.
Figure 3-1 Some of the Available HX80 Configurations
a. Stand-alone Probe
b. Remote Mount with Display
Option
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2.2 SPECIFICATIONS SUMMARY
(See Specifications for additional information)
2.2.1 STAND-ALONE PROBE
Analog Outputs: 0 – 10 Vdc (X3)
Digital Output: RS-232C
Power Supply: 18 to 30 Vdc, unregulated, 50 mA max.
RH Accuracy: +/- 1% nominal
Temp. Accuracy: +/- 0.5°C
Mounting: Cable Length: 6 feet
Fitting: ¾ inch stainless steel
NPT thermocouple fitting
Dimensions: Length: 8 inches
Diameter: ¾ inch
Materials: Housing: Stainless Steel
Filter: Sintered Stainless Steel (removable)
2.2.2 PROBE WITH ELECTRONICS UNIT
Analog Outputs: 4 to 20 mA (X3)
Digital Output: RS-232C, bi-directional
Alarm Relays: Form A (SPST, NO) X2
Power Supply: 18 to 30 Vdc unregulated, 50 mA max.
RH Accuracy: +/- 1% nominal
Temp. Accuracy: +/- 0.5°C
Electronics Housing Protection:
IP66 (NEMA 4X) Dust tight and moisture resistant
6
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Table 2-1 HX80 Series, Standard Available Configurations
MODEL NO.
HX85 X
HXB85 X
HXP85 X
HX86 X
HXB86 X
HXP86 X
HX86N x
SENSOR ONLY
SENSOR WITH
ELECTRONICS MODULE
2.3 HX80 SERIES MODEL DESCRIPTIONS
HX85 – A Humidity/Temperature probe providing RH, Dew Point, and Temperature
outputs.
HXB85 – A Humidity/Temperature/Barometric Pressure probe providing RH,
Temperature, and Pressure outputs.
HXP85 – A Humidity/Temperature/High Pressure probe providing RH, Temperature,
and Pressure outputs.
HX86 – A Humidity/ High Temperature probe providing RH, Temperature, and Dew
Point outputs, with remote Electronics Unit including Digital Display.
HXB86 – A Humidity/High Temperature/Barometric Pressure probe providing RH,
Temperature, and Pressure outputs, with remote Electronics Unit including Digital
Display.
HXP86 – A Humidity/High Temperature/High Pressure probe providing RH,
Temperature, and Pressure outputs, with remote Electronics Unit including Digital
Display.
HX86N – Identical to HX86, with Remote Electronics Unit, but with no Digital Display.
2.4 AVAILABLE OPTIONS
HX80-DIS – Remote electronics module with two-line LCD digital display, three 4 to 20
mA analog outputs, RS-232C, and two programmable alarm relays. This unit can be
added to existing Probes in the field.
HX80-NDIS – Similar to HX80-DIS but without Digital Display
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HX80- SENSOR – Field-replaceable sensor module for RH/Temperature.
Interchangeability accurate to published specification.
HXP80-SENSOR – Field-replaceable sensor module for RH/Temperature/Pressure.
Interchangeability accurate to published specification.
HXB80-SENSOR – Field-replaceable sensor module for RH/Temperature/Barometric
Pressure. Interchangeability accurate to published specification.
HX80-CHAMBER – Sample chamber with inlet and outlet fittings.
Table 2-2 HX80 Series Sensor Actual Measurement Ranges.
MODEL NO. OUTPUT 1 OUTPUT 2 OUTPUT 3
HX85
MEASUREMENT RANGE 5 to 95% -20 to +70ºC -60 to +30ºC
HXB85
MEASUREMENT RANGE 5 to +95% -20 to +75ºC 0 to 1100 MB
HXP85
MEASUREMENT RANGE 5 to +95% -20 to + 75ºC 0 to 200 psia
HX86
MEASUREMENT RANGE 5 to 95% -20 to +115ºC -40 to +60ºC
HXB86
MEASUREMENT RANGE 5 TO 95% -20 to +115ºC 0 to 1100 MB
HXP86
MEASUREMENT RANGE 5 TO 95% -20 to +115ºC 0 to 200 psia
NOTES: 1. THE STANDARD RANGES ARE FIELD PROGRAMMABLE
VIA THE RS-232 PORT.
2. SEE TABLE 5-1 FOR STANDARD FACTORY SCALING.
PERCENT RHAIR TEMP. DEW POINT
PERCENT RHAIR TEMP. BAR. PRESSURE
PERCENT RHAIR TEMP. ABS. PRESSURE
PERCENT RHAIR TEMP. DEW POINT
PERCENT RHAIR TEMP. BAR. PRESSURE
PERCENT RHAIR TEMP. ABS. PRESSURE
8
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3.0 INSTALLATION
3.1 MOUNTING THE PROBE
The Probe includes a stainless steel mounting sleeve, commonly called a thermocouple
mount. It has a tapered male ¾-inch NPT pipe thread. The female mating fitting, usersupplied, should be mounted in a gas-tight manner to a flat surface of a duct or
chamber wall containing the gas to be measured.
To install the mount and Probe:
1. Separate the two parts of the mounting sleeve.
2. Screw the front portion of the mounting sleeve (the tapered NPT fitting) into the
pre-mounted mating fitting. Teflon™ tape may be used for a good seal. Do
over-tighten.
3. Insert the Probe into the rear portion, and screw this part of the mount into the
previously mounted front portion, so that the Probe is gripped snugly. Do
over-tighten. As much of the Probe as possible should protrude inside the area
to be measured, to avoid possible laminar flow errors.
If the optional sample chamber is to be used, simply screw it down to any flat surface,
and connect ¼ inch OD tubing to the inlet and outlet compression fittings.
not
not
Figure 3-1, System with Sample Cell, ready for mounting
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3.2 MOUNTING THE REMOTE ELECTRONICS MODULE
MOUNTING CONSIDERATIONS
1. If the Digital Display has been provided, is it easily visible?
2. Is the location convenient for routing electrical wiring?
3. Is the module within 6 feet (1.8 meters) of the Sensor location?
Use a small hammer to tap in the pins that hold the four corner mounting lugs in place.
See Figure 3-2 below. Mount the box to a flat surface with screws or bolts through the 4
mounting holes.
Figure 3-2 a,b,c,d
Installing Mounting Lugs
3.3 ELECTRICAL WIRING
3.3.1 PROBE ONLY
See Wiring Table 3-1 and Figure 3-3 below.
1. Connect Power Supply wiring as shown. The Positive voltage output of the
supply is connected to the Yellow wire. The Negative output of the supply is
connected to the Green wire.
2. Connect the Analog Output wiring as shown. Three 0 to 10Vdc outputs are
available. Connect Outputs 1, 2, and 3 as required, observing the color
codes.
3. Connect the RS-232 Serial Output if desired. Only 2 wires are required if
the output is needed for transmitting information only. A third wire is
added for bi-directional communications with the serial port.
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Table 3-1 HX80 Series Probe Wiring Table
ITEM COLOR CODE
Power Supply – Pos. Yellow
Power Supply – Neg. Green
Output 1 – Pos. Brown
Output 2 – Pos. Red
Output 3 – Pos. Orange
Output Common Black
Serial Output – TX Blue
Serial Output – RX White
Serial Common Green
Figure 3-3 HX80 Series Probe Wiring Diagram
3.3.2 PROBE WITH ELECTRONICS MODULE
See Tables 3-2, 3-3, and Figure 3-4 below.
Notes:
1. Cable bushings are shipped separately. Carefully tap out the desired
knockouts, and mount the bushings.
2. We recommend that you route the Probe Cable through a bushing on the
left. Route all other wiring through the bushing on the right.
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1. Run the cable from the Probe to the connector labeled Probe Input.
2. Wire the Power Supply as shown in Table 3-2.
3. Wire the three 4 to 20 mA Analog Outputs and Alarm Relays as shown in Table
3-2 if desired.
4. Connect to the RS-232C Serial Port at J6 if desired.
Table 3-2 Electronics Unit Wiring Table
ITEM CONN. TERM.
Power Supply (+) J8 2
Power Supply (-) J8 1
Analog Out 1 (+) J9 1
Analog Out 1 (-) J9 2
Analog Out 2 (+) J9 3
Analog Out 2 (-) J9 4
Analog Out 3 (+) J9 5
Analog Out 3 (-) J9 6
Alarm Relay 1 J2 1
Alarm Relay 1 J2 2
Alarm Relay 2 J2 3
Alarm Relay 2 J2 4
Table 3-3 J6 Wiring Table
DB-9 SERIAL CONNECTOR ITEM
Pin 2 TX
Pin 3 RX
Pin 5 RTN
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A
A
Figure 3-4 Electronics Unit Wiring
PROBE CONN.
OUTPUT 1
RTN 1
OUTPUT 2
RTN 2
OUTPUT 3
RTN 3
24 VDC
NEG -
POS +
RS23
LARM 2
LARM 1
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4.0 BASIC BLOCK DIAGRAM THEORY OF OPERATION
4.1 PROBE ASSEMBLY
See Figure 4-1, the Probe Assy. Basic Block Diagram.
The Probe Assembly is a stand-alone, completely self-contained measuring system. All
units include the RH and Temperature Sensors, and some optional probes include a
Pressure Sensor as well. The field-replaceable Sensor Circuit Board has standardized
output levels for all three measured parameters. Therefore, boards may be quickly
replaced while in operation without the need for recalibration, maintaining full system
accuracy. The Microprocessor performs the system control, parameter calculation, and
serial digital communications. Digital-to-Analog (D-A) conversion provides three 0 to 10
Vdc linear Analog Outputs corresponding to the measured and/or calculated
parameters.
The serial digital RS-232 interface is bi-directional, allowing the user to not only receive
and record measured information, but to remotely control output scaling, alarm relay
setpoints, and other functions as well.
SENSOR BOARD PLUG-IN ASSY.
RH
SENSOR
TEMP.
SENSOR
PRESSURE
SENSOR
NORMALIZATION - CALIBRATION
STAGE
SENSOR BOARD PLUG-IN CONNECTOR
MICROPROCESSOR
D-AD-AD-A
0 - 10 VDC
RH OUT
0 - 10 VDC
TEMP. OUT
PRESSURE OUT
0 - 10 VDC
RS-232
(TX)
SERIAL PORT
RS-232
(RX)
Figure 4-1 Basic Block Diagram, Probe Assy
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4.2 HX80-DIS ELECTRONICS MODULE
Although the Probe may be used as a stand-alone measuring device (HX85), it also
may be connected to the type DIS remote display unit, for additional capability. This
combination is called the HX86. A complete HX86 system consists of the Probe, the
interconnecting 6 foot (1.8 meter) cable, and the electronics module. Outputs of the unit
include a Serial Port, two Alarm Relays and three 4 to 20 mA Analog Outputs. A twoline LCD Digital Display is also included.
4.3 THE COMPLETE HX86 SYSTEM
Figure 4-2 is a basic block diagram of the complete Humidity, Temperature and
Pressure measuring system. The remote Probe is connected, via the attached cable, to
the electronics module. The system is completely controlled by the microprocessor in
this module.
The three sets of analog voltage outputs from the Probe are routed through the Analog
Scaling and Selection stage. The scaling of these output signals may be programmed
by the user to any desired range by using the RS-232 Serial Port. The bi-directional
RS-232 is brought out to a connector in the electronics module. The user can also
program the two Alarm Relay set points via this digital interface. The built-in LCD
Digital Display, which provides information on all measured parameters, is also
controlled by the microprocessor. In addition, the microprocessor is used to calculate
other parameters than those directly measured by the sensors in the Probe. These may
be shown on the Digital Display, and they are also available on both the analog and
digital (RS-232) outputs. The Alarm Relays may also be set for these calculated values.
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Figure 4-2 System Basic Block Diagram
RH
SENSOR
HTPB PROBE ASSY.
DIGITAL
DISPLAY
TEMP.
SENSOR
ALARM
RELAY
#1
PRESSURE
SENSOR
(OPTION)
6 FT. SENSOR CABLE
MICROPROCESSOR
ALARM
RELAY
#2
SERIAL
PORT
(TX) (RX)
ANALOG
OUTPUTS
(0 - 10V X3)
ANALOG
SCALING
AND
SELECTION
ELECTRICAL CONNECTORS
ALARM
1
ALARM
2
USER INTERFACE
16
RS-232
(TX) (RX)
ANALO G OUTPUTS
1 2 3
Page 19
5.0 OPERATION
5.1 INITIAL BENCH TESTING
New units may be tested on the bench before installation, if desired.
For units consisting of the Probe only –
1. Connect a proper Power Supply to the correct wires.
Caution: Observe polarity!
2. Using a DC Voltmeter, measure the 0 to 10 Vdc Output and confirm that it
corresponds to the room condition. (Humidity, Temperature, etc.)
For systems consisting of the Probe and the Electronics Unit –
1. Connect the Probe to the Electronics Module.
2. Connect a proper Power Supply to the correct terminals.
Caution: Observe polarity!
3. Measure the 4 to 20 mA Output as above, or read the Digital Display.
Confirm that the reading corresponds to the room condition. (Humidity,
Temperature, etc.)
5.2 NORMAL OPERATION
Note:
This section assumes that all required electrical wiring and mounting has
been completed. See the Installation section for further information if
necessary.
Use of the HX80 series of probes is extremely simple. There are no controls to operate
during normal use, as these devices are designed for long-term unattended operation.
With the Analog Outputs, Digital Outputs, and/or Alarm Relays connected to a Data
Acquisition System, Recorder, Process Controller, Computer, or Terminal, the user has
only to periodically monitor the system for normal operation.
5.3 FACTORY DEFAULT RANGES
The scaling of the default measurement ranges may be changed in the field via the
Serial Port if required. See Section 5.4 below for range-changing instructions.
The following ranges are set at the Factory. They correspond to the three separate 0 to
10 Vdc analog outputs that are provided. The scaling of these ranges may be changed
in the field via the Serial Port if required.
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Notes:
Table 5-1 Standard Output Scaling
MODEL R.H. TEMP. PRESSURE
HX85 0 to 100% -20 to 80OC N/A
HXB85 0 to 100% -20 to 80OC 900 to 1100 mb
HXP85 0 to 100% -20 to 80OC0 to 200 psia
HX86 0 to 100%-25 to 125OCN/A
HXB86 0 to 100%-25 to 125OC900 to 1100 mb
HXP86 0 to 100%-25 to 125OC0 to 200 psia
HX86N 0 to 100% -25 to 125 OC N/A
1. Although the Factory default range for the HXB85 and the HXB86
is 900 to 1100 mb, it can be reprogrammed in the field over a range
of 0 to 1100 mb.
2. If you have the Type DIS Humidity Multi-I/O accessory, the 0 to 10
Vdc Analog Outputs may be changed in the field to either 0 to 5 Vdc
or 4 to 20 mA if desired. This is accomplished by changing DIPswitch positions on the circuit board.
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5.4 USING THE RS-232C SERIAL PORT TO PROGRAM YOUR
SETTINGS
5.4.1 SERIAL PORT SETUP
Plug a standard RS-232 cable into the DB-9 connector on the circuit board in the Type
DIS Humidity Multi I/O Electronics Unit. Plug the other end into your terminal or
computer. Use a Terminal Emulation program such as Hyperterminal. Program the
Hyperterminal settings as follows:
• Baud Rate: 19.2K
• Data Bits: 8
• Parity None
• Stop Bit 1
• Flow Control None
You should now see flowing data on your monitor,
displaying the same information as the Multi I/O front
panel Digital Display, with a rapid update rate. If you d
not, check your serial port settings and connections.
NOTE: WHEN PROGRAMMING ALPHABETIC CHARACTERS,
USE UPPER CASE ONLY.
5.4.2 CHANGING THE DIGITAL DISPLAY
You can select any measured or calculated
parameters to appear on the front panel Digital
Display. Proceed as follows:
Press the
“Escape” key
on your
keyboard. Y
will see
“D)isplay C)al
Outputs” as
shown here.
Press “D”, selecting to change the Display. (We
will C)alibrate the Outputs later.) You will then be given a choice whether to keep the
present settings or to change them. For this example, we will C)hange them. Press
ou
o
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“C”. You can then select the parameter to insert by cycling through the options using
the Space Bar. In this case, we will change VALUE 1, the Dew Point reading, from
o
DP
C to DPoF. Press Enter to save your change and advance to the next value. Next,
do the same for Air Temperature. When completed, press Enter again to save and
advance. For this example, we will choose not to
change the %RH value. Instead, press “X” for eX)it.
When programming is completed, press “A” to
accept the changes.
5.4.3 CHANGING THE OUTPUT RANGES
The next window to be seen will be the Output
Settings screen. Here, you can modify the 4 to 20
mA Analog Output ranges. To enter this mode,
press “C” for C)hange. You will see the Set Output
screen shown here.
To change Output 1, select “1”. You will see
this screen, which shows the present settings
for Output 1.
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Example: We would like to change DP
o
F to a range of -40 to 200 oF. Press Enter.
Enter -40. Press Enter again. Enter 200. Press Enter again. To Save the Changes,
press “Y” for Y)es. To accept the changes, press “A” for A)ccept.
5.4.4 PROGRAMMING THE ALARM RELAYS
The system will then step to the
Alarm Relay mode. The two relays
are Form A, (single-pole, singlethrow), normally open. You can
independently program the “ON”
point and the “OFF” point for each
relay. To enter the menu, press
“C” for C)hange.
We would like to change Alarm 2 to
these parameters:
Open > a reading of 10
Close < a reading of 10
o
o
C
C
NOTE: IN ACTUAL OPERATION YOU SHOULD PROGAM IN A SMALL OVERLAP,
SO THAT THE RELAY DOES NOT CHATTER WHEN THE MEASURED READING IS
EXACTLY AT THE SETPOINT. THIS IS CALLED “HYSTERESIS.”
Press “2” to set Alarm 2. You will note that Alarm 2 is set for Air Temperature, AT
o
C.
Under OPEN, insert 10 and press “Enter.” Under CLOSED, insert 10 and press “Enter.”
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You will be asked to Save the Changes. Press “Y” for Y)es.
Then, press “A” for A)ccept.
The program will then automatically return to the normal mode, displaying data that is
continuously updated.
5.4.5 CALIBRATING THE ANALOG OUTPUTS
If you have a precise milliammeter, you can easily calibrate the three 4 to 20 mA analog
outputs. In order to utilize this convenient capability, connect the meter in series with
one of the analog outputs and the load.
Press the “Escape” key on your keyboard, which will interrupt the data stream and give
you the choice of D)isplay or C)al Outputs. Select “C”.
In order to calibrate Output 1, press “1”. You will then be able to insert the desired
current value at the ¼ FS (25% of Full Scale) point and at the 3/4FS (75% of Full Scale)
point. For 4 to 20 mA, 1/4FS is 8 mA, and 3/4FS is 16mA.
Insert these values, pressing “Enter”
after each one. You will then see a
range of what the milliammeter s
read in order to attain the desired
accuracy.
Then select “X” for eX)it. The system
will now return to the normal data
reading mode.
hould
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6.0 MAINTENANCE
6.1 SENSOR CIRCUIT BOARD
Inside the barrel of the Sensor probe, mounted directly at the tip, is the plug-in sensor
circuit board. This board has been calibrated at the Factory for a standard output level.
Since all boards have been calibrated for the same normalized level, they may be
replaced in the field without the requirement for recalibration, while maintaining the full
published system accuracy specification.
6.1.1 REPLACING THE SENSOR CIRCUIT BOARD
See Figure 6-1. At the tip of the Sensor probe is a snap-ring, or retaining ring. It must
be removed in order to gain access to the Sensor board. There is a groove at one end
of the ring. Using a very small
screwdriver or a small knife blade
inserted into the groove in the retaining
ring, lift it out of the machined groove
in the inside of the sensor shield
barrel. The ring can then be removed,
allowing access to the interior of the
sensor assembly.
Figure 6-1 Removing the Retaining Ring
6.1.2 REMOVING THE RETAINING COMPONENTS
Figure 6-2 shows the sequence of parts that must be removed in order to gain access to
the sensor board. All are easily removed once the retaining ring is out. Store them
carefully for re-installation later in the proper sequence.
The final item to be removed in the sequence is the plug-in sensor circuit board, which
can be seen through the slot in the sensor shield. There is a small hole near the tip of
the board to aid in removal. Inserting a small screwdriver in this hole and pulling
upward gently, unplug the board from the socket built into the probe.
Note: The small humidity sensor can be seen mounted near the tip of the board.
This is fragile. Take care not to break it during board removal or installation.
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6.1.3 SENSOR REASSEMBLY
Carefully plug the new sensor circuit board into the socket, noting that it is installed at
the correct angle and properly aligned. Using a small screwdriver in the hole near the
tip, press it down sufficiently so that it is fully inserted in the socket.
Install the bushing in the direction shown in Figure 6-2. Then install the spring, O-ring,
and the sintered filter. Finally,
while pressing on the end of the
sintered filter to compress the
spring, snap the retaining ring
back into the slot on the inside
of the sensor shield. Be sure
that it is inserted completely, so
that it will securely retain the
sensor components in place.
F
i
g
ure 6-2 Sensor Exploded View
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Page 27
7.0 SPECIFICATIONS
Note: See Table 2-2 for actual measurement ranges.
HX85 (Sensor Only)