HTPB SERIES
OPERATORS MANUAL
19 Brigham Street ● Unit #8 ● Marlborough, MA USA 01752
Tel. [508] 263-5900 ● [800] 276-3729 ● Fax [508] 486-9348
h2o@edgetech.com ● www.edgetech.com
E-mail
Rev. D May 2009
1
HTPB SERIES
QUICK STARTUP GUIDE – Page 1
STARTUP
WHEN USING PROBE ONLY:
1. Mount the Probe in position to measure the desired gas.
2. Connect Probe wiring as shown below:
Notes:
Connect only the Outputs desired. See the HTPB Manual for details.
Do not apply DC Power until all wiring is completed.
Power Supply – Pos. Yellow
Power Supply – Neg. Green
Serial Output – TX Blue
Serial Output – RX White
ITEM COLOR CODE
Output 1 – Pos. Brown
Output 2 – Pos. Red
Output 3 – Pos. Orange
Output Common Black
Serial Common Green
2
HTPB SERIES
QUICK STARTUP GUIDE – Page 2
WHEN USING PROBE WITH ELECTRONICS UNIT:
1. Mount the Probe and Electronics Unit.
2. Connect cable from Probe to Electronics Unit
(if applicable).
3. Connect Power Supply to Electronics Unit.
4. Connect Analog Outputs of Electronics Unit.
5. Connect Digital Output of Electronics Unit.
6. Connect Alarm Relays of Electronics Unit.
7. Connect RS-232 Serial Port of Electronics Unit.
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
RS-232 TX J6 2
RS-232 RX J6 3
RS-232 RTN J6 5
Notes:
Connect only the Outputs desired. See the HTPB Manual for details.
Do not apply DC Power until all wiring is completed.
3
TABLE OF CONTENTS Page
1.0 Quick Startup 2
List of Illustrations 5
List of Tables 5
2.0 EdgeTech’s Commitment to Quality 6
3.0 Introduction 7
3.1 General Description 7
3.2 Specifications Summary 8
3.3 Model Descriptions 9
3.4 Available Options 10
4.0 Installation 12
4.1 Mounting the Probe 12
4.2 Mounting the Electronics Unit 13
4.3 Electrical Wiring 13
4.3.1 Probe Only 13
4.3.2 Probe with Electronics 14
5.0 Basic Block Diagram 17
5.1 Probe Assembly 17
5.2 Electronics Module 18
5.3 Complete System 18
6.0 Operation 20
6.1 Initial Bench Testing 20
6.2 Normal Operation 20
6.3 Factory Default Conditions 20
6.4 RS-232 Serial Port 21
6.4.1 Serial Port Setup 21
6.4.2 Changing the Digital Display 22
6.4.3 Changing the Output Ranges 22
6.4.4 Programming the Alarm Relays 23
6.4.5 Calibrating the Analog Outputs 24
7.0 Maintenance 25
7.1 Sensor Circuit Board 25
7.1.1 Replacing the Sensor Board 25
7.1.2 Removing Components 25
7.1.3 Sensor Reassembly 26
4
8.0 Specifications 27
9.0 Appendix 30
9.1 Warranty Information 31
9.2 Mounting Dimensions 32
9.2.1 Wall Mount 32
9.2.2 Duct Mount 33
9.3 Basic Humidity Definitions 35
LIST OF ILLUSTRATIONS Page
3-1 Some HTPB Configurations 7
4-1 System with Sample Cell 12
4-2 Installing the Mounting Lugs 13
4-3 Probe Wiring Diagram 14
4-4 Electronics Unit Wiring 16
5-1 Probe Block Diagram 17
5-2 System Block Diagram 19
7-1 Removing Retaining Ring 25
7-2 Sensor Exploded View 26
LIST OF TABLES Page
3-1 Standard Configurations 9
3-2 Measurement Ranges 11
4-1 Probe Wiring 14
4-2 Electronics Wiring 15
4-3 Serial Port Wiring 15
5
2.0 EDGETECH’S COMMITMENT TO QUALITY
Thank you for purchasing one of our products. At EdgeTech, it is our
policy to provide cost-effective products and support services that
meet or exceed you requirements, to deliver them on time, and to
continuously look for ways to improve both. We all take great pride in
the products we manufacture.
We want you to be entirely satisfied with your instrument. The
information contained in this manual will get you started. It tells you
what you need to get your equipment up and running, and introduces
its many features.
We always enjoy hearing from the people who use our products. Your
experience with our products is an invaluable source of information
that we can use to continuously improve what we manufacture. We
encourage you to contact or visit us to discuss any issues whatsoever
that relate to our products or your application.
The Employees of EdgeTech
6
3.0 INTRODUCTION
3.1 GENERAL DESCRIPTION
The Edgetech HTPB 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 HTPB system is designed for ease of installation and operation. Fieldreplaceable 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 bi-directional 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 HTPB Configurations
a. Stand-alone Probe
b. Remote Mount with Display Option
c. Wall Mount d. Duct Mount
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3.2 SPECIFICATIONS SUMMARY
(See Specifications, Chapter 8, for additional information)
3.2.1 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)
3.2.2 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
8
Table 3-1 HTPB Series, Standard Available Configurations
MODEL NO.
HT60 X
HTB60 X
HT75 X
HTB75 X
HTP75 X
HT75DIS X
HTB75DIS X
HTP75DIS X
HT115 X
HTB 115 X
HTP115 X
HT115N X
HTB115N X
HTP115N X
SENSOR ONLY
SENSOR PLUS
ELECTRONICS MODULE –
WITH DISPLAY
3.3 HTPB MODEL DESCRIPTIONS
HT60 – Humidity and Temperature probes with Electronics Unit (single unit),
providing RH, Dew Point, and Temperature outputs and Digital Display.
HTB60 – Humidity, Temperature, and Barometric Pressure probes with
Electronics Unit (single unit), providing RH, Temperature, and Barometric
Pressure outputs and Digital Display.
HT75 – A Humidity/Temperature probe providing RH, Dew Point, and
Temperature outputs.
HT75DIS – Same as above with Electronics Unit including Digital Display.
HTB75 – A Humidity/Temperature/Barometric Pressure probe providing RH,
Temperature, and Pressure outputs.
HTB75DIS – Same as above with Electronics Unit including Digital Display.
HTP75 – A Humidity/Temperature/High Pressure probe providing RH,
Temperature, and Pressure outputs.
HTP75DIS – Same as above with Electronics Unit including Digital Display.
HT115 – A Humidity/ High Temperature probe providing RH, Temperature, and
Dew Point outputs, with remote Electronics Unit including Digital Display.
9
HT115N – Identical to HT115, but Probe only without Electronics Unit.
HTB115 – A Humidity/High Temperature/Barometric Pressure probe providing
RH, Temperature, and Pressure outputs, with remote Electronics Unit including
Digital Display.
HTB115N – Identical to HTB115, but Probe only without Electronics Unit.
HTP115 – A Humidity/High Temperature/High Pressure probe providing RH,
Temperature, and Pressure outputs.
HTP115N – Identical to HTB115, but Probe only without Electronics Unit.
3.4 AVAILABLE OPTIONS
-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.
-FRSHT – Field-replaceable sensor module for RH/Temperature/Dew Point.
Interchangeability accurate to published specification.
-FRSHTP – Field-replaceable sensor module for RH/Temperature/Pressure.
Interchangeability accurate to published specification.
-FRSHTB – Field-replaceable sensor module for RH/Temperature/Barometric
Pressure. Interchangeability accurate to published specification.
-HTSC – Sample chamber with inlet and outlet fittings to accept ¼ tubing.
10
Table 3-2 HTPB Series Sensor Measurement Ranges
MODEL NO. OUTPUT 1 OUTPUT 2 OUTPUT 3
HT60
DEFAULT RANGE 0 TO 100% -40 to +60ºC -40 to +60ºC
MAX. LIMITS 0 TO 100% -40 to +60ºC -40 to +60ºC
HTB60
DEFAULT RANGE -40 to +60ºC -40 to +60ºC 900 to 1100 mB
MAX. LIMITS -40 to +60ºC -40 to +60ºC 20 to 1100 mB
HT75
DEFAULT RANGE 0 to 100% -20 to +80ºC -60 to +40ºC
MAX. LIMITS 0 to 100% -40 to +80ºC -60 to +70ºC
HTB75
DEFAULT RANGE -60 to +40ºC -20 to +80ºC 900 to 1100 mB
MAX. LIMITS -60 to +70ºC -40 to +80ºC 20 to 1100 mB
HTP75
DEFAULT RANGE -76 to +104ºF -4 to + 176ºF 0 to 200 psia
MAX. LIMITS -76 to +158ºF -40 to + 176ºF 0 to 200 psia
HT115 and HT115N
DEFAULT RANGE 0 to 100% -20 to +80ºC -60 to +100ºC
MAX. LIMITS 0 to 100% -40 to + 115ºC * -60 to +100ºC
HTB115 and HTB115N
DEFAULT RANGE -60 to +40ºC -35 to +125ºC 920 to 1080 hpa
MAX. LIMITS -60 to +95ºC -40 to +200ºC 0 to 1200 hpa
HTP115 and HTP115N
DEFAULT RANGE -80 to +80ºF 0 to +160ºF 0 to 160 psia
MAX. LIMITS - 80 to +203ºF -40 to +239ºF 0 to 225 psia
NOTES: 1. * SCALED TO +125ºC FOR USER CONVENIENCE
2. THE DEFAULT RANGES ARE FIELD PROGRAMMABLE
UP TO THE MAX. LIMITS VIA THE RS-232 PORT.
PERCENT RH AIR TEMP. DEW POINT
DEW POINT AIR TEMP. BAR. PRESSURE
PERCENT RH AIR TEMP. DEW POINT
DEW POINT AIR TEMP. BAR. PRESSURE
DEW POINT AIR TEMP. ABS. PRESSURE
PERCENT RH AIR TEMP. DEW POINT
DEW POINT AIR TEMP. BAR. PRESSURE
DEW POINT AIR TEMP. ABS. PRESSURE
11
4.0 INSTALLATION
4.1 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 Type HTSC 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 4-1, System with Sample Cell, ready for mounting
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4.2 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 4-2 below. Mount the box to a flat surface with screws or bolts through the 4
mounting holes.
Figure 4-2 a,b,c,d
Installing Mounting Lugs
4.3 ELECTRICAL WIRING
4.3.1 PROBE ONLY
See Wiring Table 4-1and Figure 4-3 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 10 Vdc 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.
13
Table 4-1 HTPB 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 4-3 HTPB Probe Wiring Diagram
4.3.2 PROBE WITH ELECTRONICS MODULE
See Tables 4-2, 4-3, and Figure 4-4 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.
14
1. Run the cable from the Probe to the connector labeled Probe Input.
2. Wire the Power Supply as shown in Table 4-2.
3. Wire the three 4 to 20 mA Analog Outputs and Alarm Relays as shown in Table
4-2 if desired.
4. Connect to the RS-232C Serial Port at J6 if desired.
Table 4-2 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 4-3 J6 Wiring Table
DB-9 SERIAL CONNECTOR ITEM
Pin 2 TX
Pin 3 RX
Pin 5 RTN
15
A
A
Figure 4-4 Electronics Unit Wiring
PROBE CONN.
OUTPUT 1
RTN 1
OUTPUT 2
RTN 2
OUTPUT 3
RTN 3
24 VDC
NEG -
POS +
RS232
LARM 2
LARM 1
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BASIC BLOCK DIAGRAM THEORY OF OPERATION
5.1 PROBE ASSEMBLY
See Figure 5-1, 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 to 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-A D-A D-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 5-1 Basic Block Diagram, Probe Assy
17
5.2 HTPB ELECTRONICS MODULE (Type DIS)
Although the Probe may be used as a stand-alone measuring device, it also may be
connected to the type DIS remote display unit, for additional capability. The complete
HTPB 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 two-line LCD Digital Display is also included.
5.3 THE COMPLETE HTPB SYSTEM
Figure 5-2 is a basic block diagram of the complete Humidity, Temperature and optional
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.
18
Figure 5-2 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
ALARM
1
ELECTRICAL CONNECTORS
ALARM
2
USER INTERFACE
RS-232
(TX) (RX)
ANALO G OUTPUTS
1 2 3
19
6.0 OPERATION
6.1 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.)
6.2 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 HTPB 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.
6.3 FACTORY DEFAULT RANGES
See Table 3-2 for information on the measurement ranges provided by the Factory.
The maximum range limits are also shown in Table 3-2.
The scaling of the default measurement ranges may be changed in the field via the
Serial Port if required. See Section 6.4 below for range-changing instructions.
20
6.4 USING THE RS-232C SERIAL PORT TO PROGRAM YOUR
SETTINGS
6.4.1 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.
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.
6.4.2 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
ou
o
21
present settings or to change them. For this example, we will C)hange them. Press
“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.
6.4.3 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.
22
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.
6.4.4 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
C
o
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.”
23
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.
6.4.5 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
24
7.0 MAINTENANCE
7.1 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.
7.1.1 REPLACING THE SENSOR CIRCUIT BOARD
See Figure 7-1. 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 7-1 Removing the Retaining Ring
7.1.2 REMOVING THE RETAINING COMPONENTS
Figure 7-2 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.
25
7.1.3 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 7-2. 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 7-2 Sensor Exploded View
26
8.0 SPECIFICATIONS
Note: See Table 3-2 for actual measurement ranges.
HT75/HT115N (Sensor Only)
Measured Parameters – RH/Temp.
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
Output Information – RH, Temp., DP
Electrical Outputs – 0 to 10 Vdc (X3)
RS-232C
HTB75/HTB115N (Sensor Only)
Measured Parameters – RH/Temp./Barometric Pressure
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
Pressure Accuracy – +/- 5 mb
Output Information – RH, Temp., Pressure
Electrical Outputs – 0 to 10 Vdc (X3)
RS-232C
HTP75/HTP115N (Sensor Only)
Measured Parameters – RH/Temp./Pressure
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
Pressure Accuracy – +/- 0.75 psi
Output Information – RH, Temp., Pressure
Electrical Outputs – 0 to 10 Vdc (X3)
RS-232C
HT60W/HT60D (Electronics Unit with Built-in Sensor)
Measured Parameters – RH/Temp.
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
Output Information – RH, Temp., DP
Electrical Outputs – 4 to 20 mA (X3)
RS-232C
Digital Display – LCD, 2-line
o
C
o
C
o
C
o
C
Alarm Relays (X2)
27
HT75DIS and HT115 (Electronics Unit with Remote Sensor)
Measured Parameters – RH/Temp.
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
o
C
Output Information – RH, Temp., DP
Electrical Outputs – 4 to 20 mA (X3)
RS-232C
Alarm Relays (X2)
Digital Display – LCD, 2-line
HTB60W/HTB60D (Electronics Unit with Built-in Sensor)
Measured Parameters – RH/Temp./Barometric Pressure
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
o
C
Pressure Accuracy – +/- 5 mb
Output Information – RH, Temp., Pressure
Electrical Outputs – 4 to 20 mA (X3)
RS-232C
Alarm Relays (X2)
Digital Display – LCD, 2-line
HTB75DIS and HTB115 (Electronics Unit with Remote Sensor)
Measured Parameters – RH/Temp./Barometric Pressure
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
o
C
Pressure Accuracy – +/- 5 mb
Output Information – RH, Temp., Pressure
Electrical Outputs – 4 to 20 mA (X3)
RS-232C
Alarm Relays (X2)
Digital Display – LCD, 2-line
HTP75DIS and HTP115 (Electronics Unit with Remote Sensor)
Measured Parameters – RH/Temp./ Pressure
RH Accuracy – +/- 1% RH
Temp. Accuracy – +/- 0.5
o
C
Pressure Accuracy – +/- 0.75 psi
Output Information – RH, Temp., Pressure
Electrical Outputs – 4 to 20 mA (X3)
RS-232C
Alarm Relays (X2)
Digital Display – LCD, 2-line
28
Electrical Outputs
Systems with Sensor only –
0 to 10 Vdc (X 3) @ 10 mA max.
RS-232C (bi-directional)
Systems with Sensor and Electronics Unit—
4 to 20 mA (X3) into 500 Ω max.
Alarm Relay (X2) Form A (SPST, NO) rated at 3A/250 Vac
RS-232C (bi-directional)
Serial Output (All Units)
RS-232C to DTE device. 19.2 kilobaud, 8 bits data, 1 stop bit, no parity
Power Requirements
18 to 30 Vdc unregulated, 50 mA max.
Dimensions
Remote Sensor – Diameter: ¾ in. OD (1.9 cm)
Length: 8 inches (20.3 cm)
Cable Length – 6 feet (1.8 meters)
Consult Factory for longer lengths.
Electronics Module, Model DIS –
Outside Dimensions (HWD)
5.1 X 3.7 X 2.2 inches (13 X 9.4 X 5.6 cm)
Mounting Centers
4.5 2 X 3.11 inches (11.5 X 7.9 cm)
Electronics Module with Built-in Sensor –
Wall Mount – Outside Dimensions (HWD)
5.1 X 5.1 X 3.0 inches (13 X 13 X 7.6 cm)
Mounting Centers
4.52 X 4.52 inches (11.5 X 11.5 cm)
Duct Mount – Outside Dimensions (HWD)
3.74 X 6.8 X 2.0 inches (95 X 17.3 X 5.1 cm)
Mounting Centers
2.7 X 6.4 Inches (6.9 X 16.2 cm)
Sensor Pressure Rating
200 psia maximum
Sensor Sintered Filter
Material – Stainless Steel
Porosity – 40 microns
29
9.0 APPENDIX
9.1 Warranty Information
9.2 Mounting Dimensions
9.3 Basic Humidity Definitions
30
9.1 WARRANTY INFORMATION
All equipment manufactured by EdgeTech is warranted against defective
components and workmanship for repair at their plant in Massachusetts, USA,
free of charge, for a period of twelve months. Malfunction due to improper use is
not covered in this warranty and EdgeTech disclaims any liability for
consequential damage resulting from defects in the performance of the
equipment. No product is warranted as being fit for a particular purpose and
there is no warranty of merchantability. This warranty applies only if (i) the items
are used solely under the operating conditions and in the manner recommended
in the instruction manual, specifications, or other literature; (ii) the items have not
been misused or abused in any manner or repairs attempted thereon; (iii) written
notice of the failure within the warranty period is forwarded to EdgeTech and the
directions received for properly identifying items returned under warranty are
followed; and (iv) the return notice authorizes EdgeTech to examine and
disassemble returned products to the extent EdgeTech deems necessary to
ascertain the cause for failure. The warranties expressed herein are exclusive.
There are no other warranties, either expressed or implied, beyond those set
forth herein, and EdgeTech does not assume any other obligation or liability in
connection with the sale or use of said products.
Equipment not manufactured by EdgeTech is supported only to the extent of
the original manufacturer’s warranties.
31
9.2 OVERALL AND MOUNTING DIMENSIONS
9.2.1 WALL MOUNT DIMENSIONS
32
9.2.2 DUCT MOUNT DIMENSIONS
33
Notes
34
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