Omega Products HX71-V2-NB Installation Manual

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HX71 SERIES

RH Probe/Transmitter

User’s Guide

HX71-NB
MODEL

HX71 MODEL

Servicing North America:

U.S.A.: Omega Engineering, Inc., One Omega Drive, P.O. Box 4047

ISO 9001 Certified

Stamford, CT 06907-0047
Toll-Free: 1-800-826-6342 Tel: [phone]
FAX: [phone] e-mail: [e-mail]

Canada: 976 Bergar

Laval (Quebec), H7L 5A1 Canada
Toll-Free: 1-800-826-6342 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

For immediate technical or application assistance:

U.S.A. and Canada: Sales Service: 1-800-826-6342/1-800-TC-OMEGA

®

Customer Service: 1-800-622-2378/1-800-622-BEST

®

Engineering Service: 1-800-872-9436/1-800-USA-WHEN

®

Mexico/ En Español: 001 [phone] FAX: [phone]
Latin America [e-mail] e-mail: [e-mail]

Servicing Europe:

Benelux: Managed by the United Kingdom Office

Toll-Free: 0800 099 3344 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

Czech Republic: Frystatska 184

733 01 Karviná, Czech Republic
Toll-Free: 0800-1-66342 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

France: Managed by the United Kingdom Office

Toll-Free: 0800 466 342 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

Germany/Austria: Daimlerstrasse 26

D-75392 Deckenpfronn, Germany
Toll-Free: 0800 6397678 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

United Kingdom: OMEGA Engineering Ltd.

ISO 9001 Certified

One Omega Drive, River Bend Technology Centre, Northbank
Irlam, Manchester M44 5BD United Kingdom
Toll-Free: 0800-488-488 TEL: [phone]
FAX: [phone] e-mail: [e-mail]

OMEGAnet®Online Service Internet e-mail

omega.com [e-mail]

It is the policy of OMEGA Engineering, Inc. to comply with all worldwide safety and EMC/EMI
regulations that apply. OMEGA is constantly pursuing certification of its products to the European New
Approach Directives. OMEGA will add the CE mark to every appropriate device upon certification.

The information contained in this document is believed to be correct, but OMEGA accepts no liability for any
errors it contains, and reserves the right to alter specifications without notice.
WAR NING: These products are not designed for use in, and should not be used for, human applications.

TABLE OF

CONTENTS

HX71 SERIES

RH Probe/Transmitter

i

Section Page

1. General Description .................................................................... 1

2. Unpacking .................................................................................... 1

3. Theory of Operation ................................................................... 2

4. Installation and Mounting ..................................................... 3-4

5. Electrical Connections ................................................................ 5

6. Wiring Examples ........................................................................ 6

7. Relative Humidity Output Calculations ................................ 6

8. RH Measured Vs Output Reading Table ................................. 7

9. Calibration and Maintenance..................................................... 8

10. Specifications ............................................................................... 9

FIGURES

HX71 SERIES
RH Probe/Transmitter

ii

Figure Page

Figure 1 Basic Transmitter Set-up

With Current Loop Output .............................................. 2

Figure 2 HX71 Dimensions .............................................................. 3

Figure 3 HX71 Mounting ................................................................ 3

Figure 4 HX71-NB Dimensions and Mounting ........................... 4

Figure 5 Current Transmitter Wiring Example

(4-20 mA) ............................................................................ 6

Figure 6 Voltage Transmitter Wiring Example

(0-1 Vdc and 0-5 Vdc) ....................................................... 6

1

General Description

1

1. General Description

The OMEGA®HX71 Series Relative Humidity Transmitter’s provide a
linearized and temperature compensated output signal of 4 to 20 mA, 0 to
1 Vdc or 0 to 5 Vdc depending upon the model selected. The output signal
has been calibrated and scaled 0 to 100% for Relative Humidity. A thin film
polymer capacitor senses relative humidity and is protected by a stainless
steel cap that is easily removed for cleaning. The Nema-4 stainless steel
enclosure and cable entry connection provides weathertight protection.

2. Unpacking

Remove the packing list and verify that you have received all your
equipment. If you have any questions about the shipment, please call
our Customer Service Department at:

1-800-622-2378 or 203-359-1660. On the web you can find us at:
omega.com e-mail: [e-mail]

When you receive the shipment, inspect the container and equipment
for any signs of damage. Note any evidence of rough handling in
transit. Immediately report any damage to the shipping agent.

The carrier will not honor any damage claims unless all shipping material
is saved for inspection. After examining and removing contents, save
packing material and carton in the event reshipment is necessary.

The following items are supplied in the box with your HX71 transmitter.

• This Manual, # M-4543 (1 ea.)

• Dewpoint Card (1 ea.)

Recommended Power Supply

For HX71-MA and HX71-MA-NB, Omega Model PST-10
For HX71-V1, HX71-V2, HX71-V1-NB and HX71-V2-NB: Omega Model
FPW-15

Complimentary Instruments

iSeries

®

Panel Meters and Controllers

Recommended Accessories

Duct/Wall Mounting Kit, OMEGA®Part No.: HX70-MKIT (For HX71­MA, HX71-V1, HX71-V2)
Transmitter Cable, OMEGA

®

Part No.: TX4-100 (100 ft)

RH Calibration Kit, OMEGA

®

Part No.: HX92-CAL

NOTE

2

3. Theory of Operation

A 4-20 mA loop is a series loop in which a transmitter will vary the
current flow depending on the input to the transmitter. In the HX71
Series the amount of current allowed to flow in the loop will vary
depending on the relative humidity or temperature being measured by
the sensor(s). Some advantages of a current output over a voltage
output is that the signal measured is less susceptible to electrical noise
interference and the loop can support more than one measuring
instrument as long as the maximum loop resistance is not exceeded.

A typical application utilizing a current loop will normally consist of a
power supply, the transmitter and a meter, recorder or controller to
measure the current flow. The loop resistance in the sum of the
measuring instruments and wire used. The maximum allowable loop
resistance for the HX71 to function properly is found by using the
following formula:

R

max

= (power supply voltage – 8 volts) ÷ 0.02 amps

EXAMPLE: (When using a 10 Vdc power supply).

R

max

= (10 – 8) ÷ 0.02 amps = 800 ohms max loop resistance

Figure 1 - Basic Transmitter Set-up With Current Loop Output

3

Theory of Operation

HX71 CABLE

RED WIRE

SHIELD WIRE

BLACK WIRE

PANEL METER

POWER SUPPLY

+

10V

–

50%

+

–

3

4. Installation and Mounting

Your HX71 Series RH Probe/Transmitter needs to be installed in
applications that allow for well circulated air flow to meet the published
specifications outlined here in this manual in Section 10.

OMEGA’s HX71 transmitter’s are designed for either wall or duct
mounting. A wall/duct mounting kit is available, OMEGA

®

Part

No.:HX90DM-KIT.

Figure 2 - HX71 Dimensions

Figure 3 - HX71 Mounting

131 (5.18)

R 16 (0.625)

DIMENSIONS: mm (in)

4

Installation and Mounting

HX71

MOUNTING BUSHING

MOUNTING SCREW

DUCT WALL

MOUNTING GASKET

MOUNTING PLATE

MOUNTING
NUT

MOUNTING

SCREW

HX71

CLAMP

NOTE

4

Figure 4 - HX71-NB Dimensions and Mounting

4

Installation and Mounting

52.6 (2.07)

65 (2.56)

50 (1.97)

45.3 (1.78)

19.5

(0.76)

38 (1.50)

MOUNTING

HOLE

4.3 (0.17) DIA.

MOUNTING HOLE

4.3 (0.17) DIA.

16 (0.62) DIA.

DIMENSIONS: mm (in)

5

5. Electrical Connections

All electrical connections and wiring should be performed by a suitably
trained professional only.

Model: HX71-MA, HX71-MA-NB

(2-Wire Current Output)

Red Wire: + Power Supply

Black Wire: 4-20 mA Output

Bare Wire: Shield, Earth Ground

Model: HX71-V1, HX71-V2, HX71-V1-NB, HX71-V2-NB

(3-Wire Voltage Output)

Red Wire: + Power Supply

Black Wire: - Power/-Output

Wire: + Output

White Bare Wire: Shield, Earth Ground

Your HX71 Series RH Probe/Transmitter has not been designed for, nor
is it recommended for, use in medical or nuclear applications.

Your HX71 Series RH Probe/Transmitter should never be installed in or
anywhere near explosive or flammable materials.

CAUTION

CAUTION

5

Electrical Connections

6

6. Wiring Examples

Current output model HX71-MA, HX71-MA-NB (4 to 20 mA)

Figure 5 - Current Transmitter Wiring Example

Voltage output models HX71-V1, HX71-V2, HX71-V1-NB, HX71-V2-NB

(0 to 1 Vdc or 0 to 5 Vdc)

Figure 6 - Voltage Transmitter Wiring Example

7. Relative Humidity Output Calculations

To calculate % Relative Humidity by measuring the current or voltage
output use the following formulas.

For 4-20 mA output:

% RH = (Current measured in milliamps – 4) ÷ 0.16

EXAMPLE: (11.04 mA – 4) ÷ 0.16 = 44% RH

For 0 to 1 Vdc output:

% RH = (Voltage measured in volts x 100)

EXAMPLE: 0.44 Vdc x 100 = 44% RH

HX71 CABLE

RED WIRE
SHIELD WIRE

BLACK WIRE

PANEL METER

POWER SUPPLY

24V

50%

+

–

+

–

WHITE WIRE

HX71 CABLE

RED WIRE

SHIELD WIRE

BLACK WIRE

PANEL METER

POWER SUPPLY

+

10V

–

50%

+

–

6

HX71 SERIES
RH Probe/Transmitter

7

8. RH Measured Vs Output Reading Table

% Relative

Output

Humidity 4-20 mA 0-1 (0-5) Vdc

5 4.8 0.05 (.25)
10 5.6 0.10 (.50)
15 6.4 0.15 (.75)
20 7.2 0.20 (1.00)
25 8.0 0.25 (1.25)

30 8.8 0.30 (1.50)

359.60.35 (1.75)

40 10.4 0.40 (2.00)
45 11.2 0.45 (2.25)
50 12.0 0.50 (2.50)
55 12.8 0.55 (2.75)
60 13.6 0.60 (3.00)
65 14.4 0.65 (3.25)
70 15.2 0.70 (3.50)
75 16.0 0.75 (3.75)

80 16.8 0.80 (4.00)
85 17.6 0.85 (4.25)

90 18.4 0.90 (4.50)
95 19.2 0.95 (4.75)

8

RH Measured Vs Output Reading Table

8

9

Calibration and Maintenance

9. Calibration and Maintenance

Calibration

Your transmitter has been factory calibrated to meet or exceed the
specifications outlined in this manual. The economical design of the
HX71 Series does not allow for field adjustment. Contact our Customer
Service Department if you believe your unit is not functioning
correctly.

Maintenance

If your Humidity transmitter will be used in a dusty environment, the
protective sensor cover may be removed for cleaning. Unscrew the
protective cover and gently blow compressed air through the cap. A
soft brush may also be used to remove dirt particles.

If the sensor is subjected to 100% condensation, it must be dried to
obtain correct readings. There will be no permanent damage or
calibration shift to the unit.

Units should not be exposed to high concentrations of ammonia or
alcohol vapors.

9

10. Specifications

Relative Humidity

Measuring Range: 5 - 95% (non-condensing)
Accuracy:* ±3.5% @ 22°C (72ºF) from 15 to 85% RH;

±4% @ 22°C (72ºF) below 15 and above
85% RH

* EMC (Electro Magnetic Compatibility)
Some of these devices may be subject to an additional reading error
of up to 2% by RFI (Radio Frequency Interference) when subjected to
a field strength of 3V/m between 625MHz and 725MHz.

Repeatability: ± 1% RH
Operating

Temperature Range: -25 to 85ºC (-13 to 185ºF)
Output:

Model HX71-MA,
HX71-MA-NB 4 to 20 mA (Scaled for 0 to 100% RH)
Model HX71-V1,
HX71-V1-NB 0 to 5 Vdc (Scaled for 0 to 100% RH)
Model HX71-V2,
HX71-V2-NB 0 to 1 Vdc (Scaled for 0 to 100% RH)

Power:

Model HX71-MA,
HX71-MA-NB 8 – 12 Vdc @ 20mA
Model HX71-V1, HX71-V2

HX71-V1-NB, HX71-V2-NB 8 – 24 Vdc @ 20mA
Max Loop Resistance: Ohms = (V supply – 8 V)/0.02 A
Sensor Type: Thin Film Polymer Capacitor

Enclosure Housing:

Tube Version: 316 Stainless Steel, NEMA 4

Enclosure Version: Polycarbonate, NEMA 4

Electrical Connections 2 m (6') 4-conductor shielded PVC

cable with stripped wire leads.

Dimensions: See “Mounting” Section

Weight: 200 g (7 oz)

Approvals: CE Marked

10

Specifications

10

NOTES:

NOTES:

HX71 SERIES
RH Probe/Transmitter

WARRANTY/DISCLAIMER

OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and
workmanship for a period of 13 months from date of purchase. OMEGA’s WARRANTY adds
an additional one (1) month grace period to the normal one (1) year product warranty to
cover handling and shipping time. This ensures that OMEGA’s customers receive maximum
coverage on each product.

If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer
Service Department will issue an Authorized Return (AR) number immediately upon phone or
written request. Upon examination by OMEGA, if the unit is found to be defective, it will be
repaired or replaced at no charge. OMEGA’s WARRANTY does not apply to defects resulting
from any action of the purchaser, including but not limited to mishandling, improper
interfacing, operation outside of design limits, improper repair, or unauthorized modification.
This WARRANTY is VOID if the unit shows evidence of having been tampered with or shows
evidence of having been damaged as a result of excessive corrosion; or current, heat, moisture
or vibration; improper specification; misapplication; misuse or other operating conditions
outside of OMEGA’s control. Components in which wear is not warranted, include but are not
limited to contact points, fuses, and triacs.

OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes
liability for any damages that result from the use of its products in accordance with
information provided by OMEGA, either verbal or written. OMEGA warrants only
that the parts manufactured by the company will be as specified and free of
defects. OMEGA MAKES NO OTHER WARRANTIES OR REPRESENTATIONS OF ANY
KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF TITLE, AND ALL
IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF
LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total
liability of OMEGA with respect to this order, whether based on contract, warranty,
negligence, indemnification, strict liability or otherwise, shall not exceed the
purchase price of the component upon which liability is based. In no event shall
OMEGA be liable for consequential, incidental or special damages.

CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1)
as a “Basic Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or
activity; or (2) in medical applications or used on humans. Should any Product(s) be used in or
with any nuclear installation or activity, medical application, used on humans, or misused in
any way, OMEGA assumes no responsibility as set forth in our basic WARRANTY/ DISCLAIMER
language, and, additionally, purchaser will indemnify OMEGA and hold OMEGA harmless from
any liability or damage whatsoever arising out of the use of the Product(s) in such a manner.

RETURN REQUESTS/INQUIRIES

Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department.
BEFORE RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN
AUTHORIZED RETURN (AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT
(IN ORDER TO AVOID PROCESSING DELAYS). The assigned AR number should then be
marked on the outside of the return package and on any correspondence.

The purchaser is responsible for shipping charges, freight, insurance and proper packaging to
prevent breakage in transit.

FOR WARRANTY

RETURNS, please have
the following information available BEFORE
contacting OMEGA:

1. Purchase Order number under which

the product was PURCHASED,

2. Model and serial number of the product

under warranty, and

3. Repair instructions and/or specific

problems relative to the product.

FOR NON-WARRANTY REPAIRS,

consult
OMEGA for current repair charges. Have the
following information available BEFORE
contacting OMEGA:

1. Purchase Order number to cover the

COST of the repair,

2. Model and serial number of theproduct, and

3. Repair instructions and/or specific problems

relative to the product.

OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible.
This affords our customers the latest in technology and engineering.

OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2010 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied,

reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without
the prior written consent of OMEGA ENGINEERING, INC.

M4543/0310

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