ROTRONIC HF3 User Manual

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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Page

1 of 27

Document title

HygroFlex HF3

Transmitters and thermo-hygrostats

User Guide

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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Page

2 of 27

Document title

Table of contents

1 Overview ............................................................................................................................................... 3

2 Mechanical configurations and dimensions ..................................................................................... 4

2.1 Display option ..................................................................................................................................... 5

3 General description ............................................................................................................................. 5

3.1 Power supply ...................................................................................................................................... 5

3.2 Measured parameters ........................................................................................................................ 5

3.3 Calculated parameters ....................................................................................................................... 6

3.4 Analog output signals (HF32 and HF33) ............................................................................................ 6

3.5 Relay outputs (HF34) ......................................................................................................................... 6

3.6 Service connector ............................................................................................................................... 7

3.7 Sensor protection (dust filter) ............................................................................................................. 7

4 User configurable settings and functions ......................................................................................... 7

4.1 Function overview .............................................................................................................................. 7

4.2 Factory default settings ...................................................................................................................... 9

5 Mechanical installation ...................................................................................................................... 10

5.1 General guidelines ........................................................................................................................... 10

5.2 Type D – through wall mount ........................................................................................................... 10

5.3 Type W – surface mount .................................................................................................................. 10

5.4 Type R and S – surface mount ......................................................................................................... 11

6 Electrical installation ......................................................................................................................... 12

6.1 General guidelines ........................................................................................................................... 12

6.2 Cable grip and cable specifications .................................................................................................. 13

6.3 Wiring ............................................................................................................................................... 13

7 Operation ............................................................................................................................................ 18

7.1 Minimum load requirements for the HF33 with voltage outputs ........................................................ 18

7.2 HF34 thermo-hygrostat .................................................................................................................... 19

8 Maintenance ................................................................ ....................................................................... 21

8.1 Service cable .................................................................................................................................... 21

8.2 Location of the service connector (mini-USB type)........................................................................... 21

8.3 Periodic calibration check ................................................................................................................. 22

8.4 Cleaning or replacing the dust filter (type D and W) ......................................................................... 22

9 Firmware updates .............................................................................................................................. 22

10 Technical data .................................................................................................................................... 23

10.1 Specifications ................................................................................................................................... 23

10.2 Dew point accuracy .......................................................................................................................... 26

11 Accessories ........................................................................................................................................ 27

12 Supporting documents ...................................................................................................................... 27

13 Document releases ............................................................................................................................ 27

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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Page

3 of 27

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Applicability:

This manual applies to all instruments of the HF3 series with firmware version 1.x, where 1.x can be 1.0, 1.1,
etc. Changes to the last digit of the version number reflect minor firmware changes that do not affect the
manner in which the instrument should be operated.

1 Overview

The HF3 transmitters and thermo-hygrostats measure temperature, relative humidity and the dew or frost
point. The HF3 series is designed for fixed installation in cost sensitive HVAC applications where conditions
are within the range of 0 to 100 %RH and -40 to 60 C (-40 to 140 F).

The HF3 features well proven sensors and a robust housing. Digital signal processing ensures consistent
product performance and also facilitates the task of field maintenance with features such as potentiometer
free - digital calibration.

Based on the ROTRONIC AirChip 3000 digital technology, the HF3 series offers the following user functions:

User configurable settings
Calculation of the dew or frost point
Humidity temperature calibration and adjustment
Simulator mode
Automatic humidity sensor test and drift compensation
Sensor failure mode
Data recording

The ability for the user to easily update the AirChip 3000 firmware means that instruments of the HF3 series
can be kept up-to-date regarding any future functionality improvement.

HF3 transmitters: two types of electronic circuit are available: HF32: 2-wire, loop powered (4…20 mA current
signal) and HF33: 3-wire (voltage or current signal). Both circuit types provide linear analog outputs signals for
transmission over a length of cable to a remote display, recorder, controller or data processing unit. The HF3
transmitters can be used to measure humidity only, temperature only or both parameters.

HF3 thermo-hygrostats: the HF34 (3-wire circuit type) is available as a thermo-hygrostat (humidity and
temperature), as a thermostat (temperature only) or as a hygrostat (humidity only).

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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Page

4 of 27

Document title

2 Mechanical configurations and dimensions

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

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Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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2.1 Display option

The LC display option is available only with type R
and type S mechanical configurations. The upper line
of the display corresponds to relative humidity or dew
/ frost point and the bottom line corresponds to
temperature.

The display can be configured to show a trend
indicator on each line:

▲: increasing value
▼: decreasing value

In the event of an alarm the display shows the
symbol [ ! ] to the right of the value.

For instructions see the following HW4 manual:
E-M-HW4v3-F2-002.

The display option for the HF33 has a backlight. The display option for the HF32 does not have a backlight.

3 General description

3.1 Power supply

Depending on the circuit type, the HF3 requires the following power supply:
a) HF32 (2-wire, loop powered): 10…28 VDC - depending on the load connected to the output(s). The

minimum supply voltage can be determined as follows:
V min = 10 V + (0.02 x Load*) *Load resistance in ohms.
For the maximum load of 500 , the minimum supply voltage is 10 + (0.02 x 500) = 20 VDC. With both

output circuits closed, the maximum current consumption is 40 mA.

b) HF33 (3-wire with analog outputs): 15 to 40 VDC (see note below) or 12 to 28 VAC. With both output

circuits closed, the maximum current consumption is 50 mA.
Note: depending on the type of output signal, the HF33 will operate with the following minimum voltage

0…1 V outputs: 5 VDC or 5 VAC
0…5 V outputs: 10 VDC or 8 VAC
0…10 V outputs: 15 VDC or 12 VAC
0…20 mA or 4 …20 mA outputs: 6 VDC or 5 VAC with 0 load

15 VDC or 12 VAC with 500 load

c) HF34 (3-wire): 8 to 40 VDC or 12 to 28 VAC. With both relays energized, the maximum current

consumption is 50 mA.

3.2 Measured parameters

The HF3 measures relative humidity with a ROTRONIC Hygromer® IN1 capacitive sensor and temperature
with a Pt100 RTD.

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

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HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

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Signal type

Maximum offset at range bottom

0…1 V

3 mV

0…5 V

50 mV

0…10 V

90 mV

0…20 mA

4 µA

4…20 mA

No offset

3.3 Calculated parameters

Using the ROTRONIC HW4 software, the HF3 can be configured by the user to calculate either the dew point
or the frost point.

3.4 Analog output signals (HF32 and HF33)

HF32 and HF33: with the ROTRONIC HW4 software any of the two analog output signals can be made to

correspond to one of the following:

Relative humidity
Temperature

Dew or frost point
Any output can also be disabled.
The scale of each analog output can be set within the numerical limits of -999.99 and 9999.99.
The D/A converters used to generate the analog output signals feature a 16-bit resolution and exhibit a small

positive offset at the bottom of the signal range as indicated below:.

HF33: the ROTRONIC HW4 software allows changing the type of output signal to one of the following: 0…20
mA, 4…20 mA, 0…1V, 0…5V or 0…10V. Both output signals are automatically configured with the same

signal type. No calibration or adjustment is required after changing the type of output signal.
In the case of voltage output signals, load requirements apply to the external device or circuit connected to the

HF3 transmitter. These requirements are defined in the “Operation” chapter

3.5 Relay outputs (HF34)

Each of the two independent SPDT relays has its own set-point which can be adjusted with a potentiometer
located on the printed circuit board. A relay is energized when the value of the monitored parameter is higher
than the corresponding set-point. Operation of each relay is indicated by a LED located on the HF34 printed
circuit board. This LED is lit when the corresponding relay is energized.

Using the ROTRONIC HW4 software any of the two relays can be made to correspond to one of the following:

Relative humidity

Temperature

Dew or frost point
If so desired, any relay can also be disabled. The minimum and maximum limits for the two adjustable set-

points (potentiometer) can be set within the numerical limits of -999.99 and 9999.99 and the dead band for
each set-point can also be adjusted.

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

Document Type

Page

7 of 27

Document title

MEASUREMENT ACCURACY AND RELIABILITY

AirChip 3000 Functions

Description

► Humidity / temperature adjustment

o 1-point or multi-point humidity calibration or adjustment
o 1-point or 2-point temperature calibration or adjustment
o Generate a time stamp for calibrations and adjustments
o Retain and view last adjustment date and adjustment values
o Generate calibration and adjustment protocols

► Automatic humidity sensor test
and optional drift compensation

Tests the humidity sensor for drift caused by contaminants and
can be used to automatically apply a correction. The test is
automatically carried out at regular intervals of time. Can be
configured, enabled, or disabled

The humidity sensor status can be verified either with the HW4
software and is shown as Good, SQ-tuned (corrected for drift) or
Bad (defective)

3.6 Service connector

The service connector is a UART digital interface (Universal Asynchronous Receiver Transmitter) with a mini­USB type connector. This allows connecting the HF3 either to a PC running the ROTRONIC HW4 software or
to a probe input of another instrument that is compatible with the HygroClip 2 (HC2) probes. In both cases a
service cable is required. See “Maintenance” for the location of the service connector and for the type of
service cable to be used.

Connecting the HF3 to a PC is used to configure the HF3, gain access to the HF3 functions such as

humidity and temperature adjustment, read data from the HF3 on the PC and update the AirChip 3000
firmware.

Connecting the HF3 to another instrument is useful only when the other instrument has its own display and

keypad (example HP23 hand-held calibrator). The connection allows showing the data measured by the
HF3 on the other instrument display and also allows using the other instrument internal menu to do for
example a humidity and temperature adjustment of the HF3.

3.7 Sensor protection (dust filter)

With the exception of models with the S configuration, the HF3 is supplied with a Polyethylene filter to protect
the sensors against dust particles and high air velocity.

4 User configurable settings and functions

The HF3 ships configured as specified on the customer order. The HF3 can be installed and used just as any
conventional humidity and temperature transmitter and most users will never need to use the HF3
configurable settings and functions.

Making use of the HF3 configurable settings and functions is entirely up to the user and the appropriate
settings depend on the user application. We have provided below a short description of the HF3 functions and
also indicated the factory default settings.

4.1 Function overview

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

Document Type

Page

8 of 27

Document title

MEASUREMENT ACCURACY AND RELIABILITY

► Data recording

The data recording function differs from a true data logging
function in the sense that the AirChip 3000 does not time stamp
the data. The data recording function can be used to investigate
events such as a sensor malfunction as well as to retrieve data
that would otherwise be lost

o Start or stop data recording - up to 2000 value pairs (%RH

and temperature). Starting a recording session erases all
previously recorded data

o The recording mode and log interval can be specified
o When the device is powered off, the recording session is

paused but not ended As long as the recording session has
not been ended, the device automatically resumes recording
data when powered up again

o The recorded data can be downloaded to a PC with the

HW4 software, time stamped and viewed

MEASUREMENT LOOP VALIDATION

AirChip 3000 Functions

Description

► Simulator mode

Used to generate fixed values for the humidity, temperature and
calculated parameter. Can be configured, enabled or disabled

DEVICE SAFEGUARDS

AirChip 3000 Functions

Description

► Device write protection

Used to protect the device with a password to prevent
unauthorized digital access by a digital user. Can be configured,
enabled or disabled

PROCESS PROTECTION / PROTECTION OF OTHER DEVICES

AirChip 3000 Functions

Description

► Limit humidity output to 100 %RH

Used to prevent the humidity signal from exceeding
100 %RH when condensation forms on the sensor. Can be
enabled or disabled

► Out-of-limit value alarm

Used to specify the normal range for humidity, temperature and
the calculated parameter depending on the user application.
Can be configured, enabled or disabled

Out-of-limit values trigger a digital alarm which can be also be
seen on the optional display

► Bad sensor alarm

Built-in function. Cannot be disabled
A bad humidity or temperature sensor triggers a digital alarm

which can be also be seen on the optional display

► Fail safe mode

Used to specify a "safe" fixed value for humidity and for
temperature in the event of a sensor failure. Can be configured,
enabled or disabled

© 2009-2011; Rotronic AG E-M-HF3-V1_22

E-M-HF3-V1_22

Rotronic AG
Bassersdorf, Switzerland

Document code

Unit

HygroFlex HF3 Transmitters and Thermo­hygrostats: User Guide

Instruction Manual

Document Type

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9 of 27

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Configurable Settings

Applicability

Factory default

Unit system (Metric or English)

HF32, HF33, HF34

As per ordering code

Analog signal type (4…20 mA or other)

HF33

As per ordering code

Psychrometric calculation

HF32, HF33, HF34

As per ordering code

Output 1 parameter, scale and unit

HF32, HF33

As per ordering code (%RH or DP)

Output 2 parameter, scale and unit

HF32, HF33

Temperature, unit as per ordering code

Relay 1 set-point potentiometer adjust. span

HF34

As per order (%RH or DP)

Relay 2 set-point potentiometer adjust. span

HF34

As per order (temperature)

Display resolution (optional)

HF32-S, HF33-S

1 decimal

Display backlight (optional)

HF33-S

Always on

Displayed parameters

HF32, HF33

As per ordering code

Trend indicator (display)

HF32-S, HF33-S

Enabled

Device name

HF32, HF33, HF34

Instrument model

Functions

Applicability

Factory default

Humidity / temperature adjustment

HF32, HF33, HF34

Device write protection

HF32, HF33, HF34

Disabled

Limit humidity output to 100 %RH

HF32, HF33

Enabled

Out-of-limit value digital / display alarm

HF32-S, HF33-S

Disabled

Data recording

HF32, HF33, HF34

Enabled (loop mode – 10 min. interval)

Automatic humidity sensor test

HF32, HF33, HF34

Disabled

Humidity sensor drift compensation

HF32, HF33, HF34

Disabled

Fail safe mode

HF32, HF33, HF34

Disabled

Simulator mode

HF32, HF33

Disabled

4.2 Factory default settings

Note: Configuration of the HF3 by the user and access to its functions requires a PC with the ROTRONIC

HW4 software (version 2.1.1 or higher) installed. Service cable AC3006 or AC3009 is used to connect the
HF3 service connector to a USB port of the PC (see Maintenance > Service Cable).

o For a detailed description of all AirChip 3000 / HF3 main functions see document E-T-AC3000-DF-V1
o Instructions regarding the configuration of the HF3 and access to its functions are provided in the

following manuals:

E-M-HW4v3-Main
E-M-HW4v3-F2-002
E-M-HW4v3-DR-001
E-M-HW4v3-A2-001
E-M-AC3000-CP

.

o The factory default setting for dew / frost point calculation is frost point below freezing

© 2009-2011; Rotronic AG E-M-HF3-V1_22