TSI/Alnor HM675 User manual

HYDRONIC MANOMETER

MODEL HM675

OWNER’S MANUAL

P/N 6006821, REVISION E

MARCH 2022

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

Start Seeing the Benefits

of Registering Today!

Thank you for your TSI® instrument purchase. Occasionally, TSI®
releases information on software updates, product enhancements and
new products. By registering your instrument, TSI® will be able to send
this important information to you.

As part of the registration process, you will be asked for your comments
on TSI products and services. TSI’s customer feedback program gives
customers like you a way to tell us how we are doing.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

M a n u a l H i s t o r y

The following is a manual history of the Hydronic Manometer
Model HM675 Owner’s Manual (P/N 6006821).

Revision Date

A May 2013
B June 2015
C February 2016
D February 2017
E March 2022

ii Hydronic Manometer Model HM675

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

Part Number

Copyright

Address

Fax No.

E-mail Address

Limitation of Warranty
and Liability
(effective February 2015)

Warranty

6006821 / Revision E / March 2022

©TSI Incorporated / 2013–2022 / All rights reserved.

TSI Incorporated /

(For country-specific terms and conditions outside of the USA, please visit

Seller warrants the goods, excluding software, sold hereunder, under normal use
and service as described in the operator's manual, to be free from defects in
workmanship and material for twenty-four (24) months, or if less, the length of time
specified in the operator's manual, from the date of shipment to the customer. This
warranty period is inclusive of any statutory warranty. This limited warranty is
subject to the following exclusions and exceptions:

a. Hot-wire or hot-film sensors used with research anemometers, and certain other

components when indicated in specifications, are warranted for 90 days from the
date of shipment;

b. Pumps are warranted for one year or 3000 hours; whichever comes first;

c. Parts repaired or replaced as a result of repair services are warranted to be free

from defects in workmanship and material, under normal use, for 90 days from the
date of shipment;

d. Seller does not provide any warranty on finished goods manufactured by others or

on any fuses, batteries or other consumable materials. Only the original
manufacturer's warranty applies;

e. This warranty does not cover calibration requirements, and seller warrants only that

the instrument or product is properly calibrated at the time of its manufacture.
Instruments returned for calibration are not covered by this warranty;

f. This warranty is VOID if the instrument is opened by anyone other than a factory

authorized service center with the one exception where requirements set forth in the
manual allow an operator to replace consumables or perform recommended cleaning;

g. This warranty is VOID if the product has been misused, neglected, subjected to

accidental or intentional damage, or is not properly installed, maintained, or cleaned
according to the requirements of the manual. Unless specifically authorized in a
separate writing by Seller, Seller makes no warranty with respect to, and shall have
no liability in connection with, goods which are incorporated into other products or
equipment, or which are modified by any person other than Seller.

The foregoing is IN LIEU OF all other warranties and is subject to the LIMITATIONS
stated herein. NO OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR

PARTICULAR PURPOSE OR MERCHANTABILITY IS MADE. WITH RESPECT TO
SELLER’S BREACH OF THE IMPLIED WARRANTY AGAINST INFRINGEMENT,
SAID WARRANTY IS LIMITED TO CLAIMS OF DIRECT INFRINGEMENT AND
EXCLUDES CLAIMS OF CONTRIBUTORY OR INDUCED INFRINGEMENTS.
BUYER’S EXCLUSIVE REMEDY SHALL BE THE RETURN OF THE PURCHASE
PRICE DISCOUNTED FOR REASONABLE WEAR AND TEAR OR AT SELLER’S
OPTION REPLACEMENT OF THE GOODS WITH NON-INFRINGING GOODS.

TO THE EXTENT PERMITTED BY LAW, THE EXCLUSIVE REMEDY OF THE USER
OR BUYER, AND THE LIMIT OF SELLER'S LIABILITY FOR ANY AND ALL LOSSES,
INJURIES, OR DAMAGES CONCERNING THE GOODS (INCLUDING CLAIMS
BASED ON CONTRACT, NEGLIGENCE, TORT, STRICT LIABILITY OR

iii

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

OTHERWISE) SHALL BE THE RETURN OF GOODS TO SELLER AND THE

Trademarks

TSI and the TSI logo are registered trademark of TSI Incorporated in the United
States and may be protected under other country’s trademark registrations.
CompuDat is a trademark of TSI Incorporated. Microsoft, Excel, Windows, and Vista
are registered trademarks of Microsoft Corporation.

REFUND OF THE PURCHASE PRICE, OR, AT THE OPTION OF SELLER, THE
REPAIR OR REPLACEMENT OF THE GOODS. IN THE CASE OF SOFTWARE,
SELLER WILL REPAIR OR REPLACE DEFECTIVE SOFTWARE OR IF UNABLE TO
DO SO, WILL REFUND THE PURCHASE PRICE OF THE SOFTWARE. IN NO

EVENT SHALL SELLER BE LIABLE FOR LOST PROFITS, BUSINESS
INTERRUPTION, OR ANY SPECIAL, INDIRECT, CONSEQUENTIAL OR
INCIDENTAL DAMAGES. SELLER SHALL NOT BE RESPONSIBLE FOR

INSTALLATION, DISMANTLING OR REINSTALLATION COSTS OR CHARGES. No
Action, regardless of form, may be brought against Seller more than 12 months after a
cause of action has accrued. The goods returned under warranty to Seller's factory shall
be at Buyer's risk of loss, and will be returned, if at all, at Seller's risk of loss.

Buyer and all users are deemed to have accepted this LIMITATION OF WARRANTY
AND LIABILITY, which contains the complete and exclusive limited warranty of Seller.
This LIMITATION OF WARRANTY AND LIABILITY may not be amended, modified or
its terms waived, except by writing signed by an Officer of Seller.

Find Quality Products Online at: [e-mail]

iv Hydronic Manometer Model HM675

www.GlobalTestSupply.com

C o n t e n t s

Manual History ............................................................................................ ii

Warranty ..................................................................................................... iii

About This Manual .................................................................................... iii

Formatting and Typography .................................................................. iii

Technical Assistance—Help! ................................................................ iii

Safety Information ...................................................................................... v

Labels ..................................................................................................... v

Description of Caution/Warning Symbols ............................................. vi

Caution ............................................................................................... vi

Warning .............................................................................................. vi

Caution or Warning Symbols ............................................................. vi

CHAPTER 1 Introduction ........................................................................ 1-1

Instrument Description ........................................................................ 1-2

Unpacking ........................................................................................... 1-3

CHAPTER 2 Instrument Operation ........................................................ 2-1

Keypad ................................................................................................ 2-1

Powering the Instrument ..................................................................... 2-2

Using the AC Adapter ...................................................................... 2-2

Battery Installation ........................................................................... 2-3

Battery Charging .............................................................................. 2-4

Zeroing the Manometer ....................................................................... 2-6

Zeroing the Gauge Pressure Sensor ............................................... 2-6

Zeroing the Differential Pressure Sensor ........................................ 2-6

Connecting the Manometer to the Test Points.................................... 2-7

Attaching the Hoses to the Manometer ........................................... 2-7

Bleeding the Entrained Air ............................................................... 2-7

Attaching the Hoses to the Test Points ........................................... 2-8

Performing Pressure Measurements .................................................. 2-8

Pressure Measurement Screen ....................................................... 2-8

Continuous Measurements .............................................................. 2-9

Discrete Pressure Measurements ................................................... 2-9

Performing Temperature Measurements .......................................... 2-10

Connecting the Temperature Probe .............................................. 2-10

Disconnecting the Manometer from the Test Points ......................... 2-10

CHAPTER 3 Maintenance and Troubleshooting .................................. 3-1

Routine Maintenance .......................................................................... 3-1

Draining the Hoses .......................................................................... 3-1

Draining the Manometer Valve ........................................................ 3-1

In-Line Flow Restrictor ..................................................................... 3-2

Cleaning the In-line Flow Restrictors ............................................... 3-2

Cleaning the Instrument Housing .................................................... 3-3

i

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

Calibration ........................................................................................... 3-3

Troubleshooting .................................................................................. 3-4

Technical Contacts .............................................................................. 3-5

APPENDIX A Specifications .................................................................. A-1

APPENDIX B Compliance ...................................................................... B-1

ii Hydronic Manometer Model HM675

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

A b o u t T h i s M a n u a l

This manual explains how to set up, operate, and maintain the TSI®
Incorporated Hydronic Manometer Model HM675. Please read it thoroughly
before using the instrument.

F o r m a t t i n g a n d T y p o g r a p h y

• Step-by-step instructions are numbered: 1, 2, 3, etc., set flush-left
against the inside margin.

• References to keys on the manometer and the instrument's displayed
readout are represented in bold typeface. In addition to the different
typeface, displayed messages appear in quotes.

T e c h n i c a l A s s i s t a n c e — H e l p !

For technical assistance or questions about the instrument or this manual,
or if the HM675 Hydronic Manometer needs repair or recalibration, call
Technical Support at [phone] or [phone].

iii

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

I M P O R T A N T

There are no user-serviceable parts inside the instrument. Refer all repair
and maintenance to a qualified factory-authorized technician. All
maintenance and repair information in this manual is included for use by a
qualified factory-authorized technician.

1. Serial number label
(back panel) )

2. Calibration label
(back panel)

3. European symbol for
non-disposable item.
Item must be recycled.

S a f e t y I n f o r m a t i o n

Carefully read each of the following safety warnings prior

to using the HM675 Hydronic Manometer.

This section gives instructions to promote safe and proper handling of the
HM675 Hydronic Manometer.

L a b e l s

Identification and calibration labels are attached to the outside of the
hydronic manometer housing.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

v

D e s c r i p t i o n o f C a u t i o n / W a r n i n g S y m b o l s

C A U T I O N

Failure to follow the procedures prescribed in this manual might result in

irreparable equipment damage. Important information about the operation
and maintenance of this instrument is included in this manual.

W A R N I N G

Warning means that unsafe use of the instrument could result in

serious injury to you or cause damage to the instrument. Follow the
procedures prescribed.

Warns that uninsulated voltage within the instrument may
have sufficient magnitude to cause electric shock.
Therefore, it is dangerous to make contact with any part
inside the instrument.

Warns that the instrument is susceptible to electro-static
dissipation (ESD) and ESD protection procedures should be
followed to avoid damage.

Indicates the connector is connected to earth ground and
cabinet ground.

W A R N I N G S

• NEVER use the HM675 Hydronic Manometer or accessories on
potable water systems or other systems which may be used to convey
fluids for human or animal consumption.

• NEVER charge non-rechargeable batteries by setting battery-type
selection switch to NiMH when using alkaline or other non­rechargeable batteries. Fire, explosions, or other hazards may result.

Appropriate caution/warning statements are used throughout the manual
and on the instrument that require you to take cautionary measures when
working with the instrument.

Caution

Warning

Caution or Warning Symbols

The following symbols may accompany cautions and warnings to indicate
the nature and consequences of hazards:

Carefully read each of the following safety warnings prior

to using the HM675 Hydronic Manometer.

Find Quality Products Online at: [e-mail]

vi Hydronic Manometer Model HM675

www.GlobalTestSupply.com

C A U T I O N S

• NEVER use the HM675 Hydronic Manometer to measure the
pressure of volatile, flammable, or otherwise hazardous fluids or
gasses. The instrument is not designed to be intrinsically safe, nor is it
designed for use with caustic or corrosive chemicals.

• NEVER connect the HM675 Hydronic Manometer or accessories to
systems which exceed the instrument’s maximum pressure
specification (300 psi; 2068 kPa).

• Observe proper safety precautions and wear appropriate personal
protective equipment, including gloves and eyewear, when working
on high pressure or high temperature systems. Ruptured or leaking
lines pose a potential risk of serious personal injury.

• When using the HM675 Hydronic Manometer, verify all hose
connections are secure prior to taking pressure measurements.
Loose connections may result in the discharge of pressurized water
or air, posing a potential risk of serious personal injury.

• Exercise caution when disconnecting the HM675 Hydronic
Manometer from a pressurized system. Water or air discharged under
pressure poses a potential risk of severe injury.

• Exercise caution in using the HM675 Hydronic Manometer near
electrical equipment. Water spray associated with purging or
disconnecting hoses presents a potential risk of damage to such
equipment.

• Thoroughly drain and dry the HM675 Hydronic Manometer hoses and
internal piping after each use. This will help in limiting the potential for
growth of hazardous microorganisms.

• NEVER plug into the instrument any power supply other than the one
provided with the instrument.

• ALWAYS make certain that the battery switch is in the correct
position for the type of battery being used (Alkaline/NiMH). Failure to
do so may result in Fire, Explosions or other hazard.

• NEVER use Alkaline and NiMH batteries together on the same
instrument.

• ALWAYS use the hoses with the provided Flow Restrictor connected
in line with the shut-off valves to prevent “Water Hammer.” Water
Hammer is a fast moving shock wave of pressure caused by sudden
changes in the system such as a valve being opened or closed or a
pump being turned on or off.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

vii

C H A P T E R 1

I n t r o d u c t i o n

The HM675 Hydronic Manometer is an easy-to-use instrument designed
for the accurate measurement of pressure in non-potable water and air
systems. Features of the manometer include the following:

• Single-function keys for ease of use

• Simultaneous measurement and display of High-side gauge and

Differential pressure

• Calculation and display of Low-side gauge pressure

• User-selectable units of measure

• User-selectable time constant

• Easy to read LCD with backlight

• Power input via AC adapter or batteries (alkaline or

rechargeable NiMH)

• Internal NiMH battery charging

• Automatic power shutoff

• Splash-proof case

• Rugged carrying case for storage of meter, hoses, accessories, tools,

and paperwork

1-1

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

I n s t r u m e n t D e s c r i p t i o n

• Meter

• Hard carrying case

• (2) 6-foot (1.8 m)

hoses with shut-off
valves

• (2) P/T gauge
adapter probes

• (2) B&G readout
probes

• (2) ¼” Flare male ×
¼” male NPT
fittings

• (2) Female ¼” NPT
to Male ¼” ISO
Parallel Pipe
Threads

• (2) Female ¼” NPT
to Male ¼” ISO
Tapered Pipe
Threads

• AC adapter

• (4) NiMH batteries,

neck strap

• Owner’s manual

• NIST traceable

certificate

Keypad

Bottom Port Cover

AC Power
Adapter
Input Port

USB Port (for

factory calibration)

LCD Display

Temperature Probe
Port 2

Temperature Probe

Port 1

Pressure

Ports

Neck/Hanging
Strap Clips

Valve Handle

The HM675 Hydronic Manometer includes:

An accessory temperature probe is available as an optional tool for the
HM675 Hydronic Manometer. The 18” diameter, stainless steel sheathed
immersion probe is designed for measurement of water line temperatures.

Figure 1-1
HM675 Meter Description

Find Quality Products Online at: [e-mail]

1-2 Hydronic Manometer Model HM675

www.GlobalTestSupply.com

U n p a c k i n g

Item

Part No.

Carrying case

1319409

Blue and red hose kit with shut-off valves and flow restrictor

6006813

P/T gauge adapter probes (2)

632360004

B&G readout probes (2)

632360010

AC adapter

6009857

AA-size NiMH battery, four required

1208048

Battery holder

1801206

Neck strap

2913011

Owner’s manual

1980517

Pocket screw driver

3012054

Item

Part No.

Accessory fittings kit (USA only)

HMFIT

4 in. (10 cm) long, 0.125 in. (3.175 mm) dia. Temperature probe

801290

External battery charger with (4) AA NiMH batteries (USA only)

801093

As you unpack the instrument and accessories, check the components
against your packing list. If any parts are missing or damaged, notify TSI®
immediately. Tables 1-1 and 1-2 list available standard and optional

components for the HM675 Hydronic Manometer.

Table 1-1

Standard Components

Table 1-2

Optional Components

Please register your HM675 promptly through our website at
Registration of your product allows us to notify you of product
updates.

Introduction 1-3

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

K e y p a d

READ

Pressing the READ key initiates taking a time-averaged
reading based on the current setting of the time constant
(TC). Upon taking the reading, the values are displayed on­screen for a period of ten (10) seconds.

UNITS
GAUGE

Pressing the UNITS GAUGE key allows for toggling through
the available units for gauge pressure measurements (High
P and Low P). The available units of measurement are: psi,
inH2O, ftH2O, inHg, kPa, mH2O, mmHg, and bar.

UNITS ΔP

Pressing the UNITS ∆P key allows for toggling through the
available units for differential pressure measurements (dP).
The available units of measurement are: psi, inH2O, ftH2O,
inHg, kPa, mH2O, mmHg, and bar.

NOT I C E

When using the accessory temperature probe, the unit of
measurement for temperature (°F or °C) is driven by the
selected unit of measurement for differential pressure:

• Differential pressure in psi, inH2O, ftH2O, or inHg →
temperature in °F

• Differential pressure in kPa, mH2O, mmHg, or bar →
temperature in °C

ZERO
GAUGE

Pressing the ZERO GAUGE key initiates zeroing of the
gauge pressure sensor.

NOT I C E

Proper zeroing of the gauge pressure sensor is achieved
with the High pressure (+) port open to atmosphere and
the valve handle in the MEASURE position.

C H A P T E R 2

I n s t r u m e n t O p e r a t i o n

Each key and its function are described below.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

2-1

TIME
CONSTANT

Pressing the TIME CONSTANT key allows for toggling
through the available settings for the time constant (TC) as
follows: 1, 5, 10, 20, and 30 seconds. The current setting of
the time constant is indicated on the display.

NOT E S

• The time constant is the sampling period over which
the manometer averages pressure measurements.
Example: with the time constant equal to 10 seconds,
the displayed reading represents the average of
measurements taken over the previous 10 seconds.

• Increasing the time constant will serve to improve
measurement stability, particularly when measuring
systems with fluctuating pressures.

CONTRAST


Press the CONTRAST ▲ key to increase the display
contrast.

CONTRAST


Press the CONTRAST ▼ key to decrease the display
contrast.

Press the key to turn the HM675 Hydronic Manometer
on or off.

Press the BACKLIGHT key to turn the display’s backlighting
on or off.

NOT I C E

Backlighting has a significant impact on battery life. Use
backlighting only when working in areas where you
cannot read the display with existing light.

P o w e r i n g t h e I n s t r u m e n t

The HM675 Hydronic Manometer can be powered by four (4) AA-size
batteries (alkaline or rechargeable NiMH) or the AC adapter.

Using the AC Adapter

The AC adapter allows the HM675 Hydronic Manometer to be powered
from a standard AC wall outlet. When using the AC adapter, alkaline
batteries (if installed) will be bypassed. The AC adapter also charges the

Find Quality Products Online at: [e-mail]

2-2 Hydronic Manometer Model HM675

NiMH type batteries (if installed) in the unit.

NOT ICE

With the battery-type selection switch set to NiMH, the manometer will
initiate charging the batteries whenever the AC adapter is connected.

www.GlobalTestSupply.com

C A U T I O N S

• Only use TSI P/N 6009857, the AC adapter supplied with the

instrument, when powering the HM675 Hydronic Manometer
externally. DO NOT connect the AC adapter or car adapter provided

with the battery optional charger (801093) or any other AC adapter to
the HM675/685. Using any other power cable or power supply may
cause damage to the device and void the warranty.

• NEVER plug into the instrument any power supply other than the one
provided with the instrument.

W A R N I N G

NEVER charge non-rechargeable batteries by setting battery-type

selection switch to NiMH with alkaline or other non-rechargeable
batteries. Fire, explosions, or other hazards may result.

Battery Type
Selection Switch

Battery Installation

To install/replace the batteries:

1. Turn the manometer off and locate the battery cover on the back of
the unit.

2. Loosen the screw on the battery compartment cover and lift to remove.

3. Remove the battery holder. Tapping the backside of the meter against
your hand may assist in removing the battery holder.

4. Remove the old batteries and replace with fresh batteries (alkaline or
rechargeable NiMH). Ensure that the batteries are correctly oriented
within the battery holder.

5. Set the battery-type selection switch to indicate the type of batteries to
be used (alkaline or rechargeable NiMH).

Figure 2-1

Find Quality Products Online at: [e-mail]

Location of Battery-Type Selection Switch

Instrument Operation 2-3

www.GlobalTestSupply.com

W A R N I N G

DO NOT use Lithium batteries in this instrument. Fire, explosions, or other

hazards may result.

C A U T I O N S

• NEVER use Alkaline and NiMH batteries together on the same
instrument.

• ALWAYS make certain that the battery switch is in the correct
position for the type of battery being used (Alkaline/NiMH).
Failure to do so may result in Fire, Explosions, or other hazard.

W A R N I N G

DO NOT use Lithium batteries in this instrument. Fire, explosions, or

other hazards may result.

6. Reinstall the battery holder. Ensure the battery holder orientation is
such that its terminals make contact with the spring contacts within the
battery compartment.

7. Replace the battery compartment cover.

NOT ICES

• The NiMH batteries included with the instrument may require
recharging prior to first use.

• Fully charged batteries should enable the instrument to operate for a
period of at least twelve (12) hours.

• Setting the battery-type selection switch properly will prevent unwanted
charging of non-rechargeable alkaline batteries and provide charging
of NiMH batteries when the AC adapter is connected.

• A battery charge life remaining indicator is shown on the display
whenever the manometer is powered by batteries, and turned on.

• When using NiMH batteries, the indicator of battery charge life
remaining will not be accurate due to their inherent non-linear voltage
drop with power use.

• Due to the danger of battery leakage, remove batteries from the battery
compartment prior to storage.

• NEVER mix battery types.

• For maximum battery life, ensure backlight is “off” when not needed.

Battery Charging

Find Quality Products Online at: [e-mail]

2-4 Hydronic Manometer Model HM675

www.GlobalTestSupply.com

C A U T I O N S

• NEVER plug into the instrument any power supply other than the
one provided with the instrument.

• ALWAYS make certain that the battery switch is in the correct
position for the type of battery being used (Alkaline/NiMH). Failure
to do so may result in Fire, Explosions or other hazard.

• NEVER use Alkaline and NiMH batteries together on the
same instrument.

The HM675 Hydronic Manometer allows for internal charging of AA-size
type NiMH (only) batteries. Charging of the batteries is initiated as follows:

1. Turn the manometer off and locate the battery cover on the back of
the unit.

2. Loosen the screw on the battery compartment cover and lift to remove.

3. Remove the battery holder. Tapping the backside of the meter against
your hand may help in removing the battery holder.

4. Verify the batteries installed are rechargeable type NiMH.

5. Set the battery-type selection switch to NiMH (see Figure 2-1).

6. Reinstall the battery holder. Ensure the battery holder orientation is
such that its terminals make contact with the spring contacts within the
battery compartment.

7. Replace the battery compartment cover.

8. Plug in the AC adapter.

NOT ICES

• Full charge of the batteries is achieved within four (4) hours.

• Fully charged batteries should enable the instrument to operate for a

period of at least twelve (12) hours.

• The manometer remains fully operational while charging batteries.

• NEVER attempt to charge battery types other than AA-size

rechargeable NiMH.

• For maximum battery life, ensure the backlight is “off” when not
needed.

• NEVER mix battery types.

• NiMH batteries should only be charged at room temperature. Starting

with batteries that are too cold or too warm can cause the charge cycle
to terminate early.

Find Quality Products Online at: [e-mail]

Instrument Operation 2-5

www.GlobalTestSupply.com

Z e r o i n g t h e M a n o m e t e r

The HM675 Hydronic Manometer is equipped with both a gauge and
differential pressure sensor, allowing for simultaneous measurement and
display of High-side gauge and Differential pressure. The gauge and
differential pressure sensors are zeroed independently of one another.

Zeroing the Gauge Pressure Sensor

To ensure the most accurate gauge pressure (High P) measurements, the
HM675 gauge pressure sensor should be zeroed prior to taking readings
on each new system. The gauge pressure sensor is zeroed as follows:

1. Disconnect the High pressure (red) hose from the manometer such
that the High pressure (+) port is open to atmosphere.

2. Turn the valve handle on the manometer to the MEASURE position.

3. Press the ZERO GAUGE key. Follow on screen instruction to zero the
gauge pressure sensor.

4. Allow the manometer to stand undisturbed for five (5) seconds until the
zero gauge pressure sensor function has completed.

• Zeroing the gauge pressure sensor requires you to disconnect the High
pressure (red) hose; as such it is often most convenient to zero the
gauge pressure sensor as part of the start-up sequence (i.e., before
hoses have been connected).

• The zero offset of the gauge pressure sensor is sensitive to
temperature changes. If moving the manometer between areas of
extreme temperature difference, it is best to allow the meter to settle to
the new temperature prior to zeroing.

NOT ICES

Zeroing the Differential Pressure Sensor

To ensure the most accurate differential pressure (dP) measurements, the
HM675 differential pressure sensor should be zeroed prior to taking
readings on each new system. The differential pressure sensor is zeroed
as follows:

1. Go to the Measurement Screen.

2. Turn the valve handle on the manometer to the BYPASS position.

3. The instrument will automatically zero the differential pressure sensor.
Follow the on-screen instructions and return the knob to MEASURE
once this is done.

2-6 Hydronic Manometer Model HM675

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

NOT ICES

• Any pressures applied to the hoses will not affect the dP zeroing
function. This feature allows for successful zeroing of the differential
pressure sensor while maintaining connections to the system
under test.

• Zeroing of the differential pressure sensor is initiated any time the
valve handle has been turned to the BYPASS position with the meter
turned on. This feature allows for successful zeroing of the differential
pressure sensor while entrained air is being purged from the hoses.

• The zero offset of the differential pressure sensor is sensitive to
temperature changes. If moving the manometer between areas with
extreme temperature difference, it is best to allow the meter to settle to
the new temperature prior to zeroing.

C o n n e c t i n g t h e M a n o m e t e r t o t h e T e s t P o i n t s

Attaching the Hoses to the Manometer

1. Connect the straight female flare fitting on the High pressure (red)
hose to the male fitting on the top of the manometer marked with a plus
(+) sign.

2. Connect the straight female flare fitting on the Low pressure (blue)
hose to the male fitting on the top of the manometer marked with a
minus (-) sign.

Bleeding the Entrained Air

To ensure the most accurate pressure measurements, purge all entrained
air within the hoses as follows:

1. Turn the shut-off ball valve on both the High and Low pressure hoses
to the closed position.

2. Turn the valve handle on the manometer to the MEASURE position.

3. Using an appropriate fitting, connect the open end of the High pressure
(red) hose to the test point with the higher line pressure.

4. Attach the appropriate fitting to the open end of the Low pressure
(blue) hose.

5. To ensure all the air is bled from the hoses, hold the open end of the
Low pressure (blue) hose in an upright position over a suitable
receptacle or near a drain.

6. Turn the shut-off ball valve on both the High and Low pressure hoses
to the open position.

7. Turn the valve handle on the manometer to the BYPASS position to
allow the liquid flow to displace the entrained air.

Instrument Operation 2-7

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

NOT ICE

Zeroing of the differential pressure sensor is initiated any time the valve
handle has been turned to the BYPASS position with the meter turned on.
This feature allows for successful zeroing of the differential pressure
sensor while entrained air is being purged from the hoses.

8. Once the liquid is flowing steadily from the Low pressure (blue) hose,
turn the valve handle on the manometer to the MEASURE position.

NOT ICE

The time to fully prime the hose with fluid may take up to one minute
depending on the line pressure. Higher line pressure will reduce the
bleed time.

Attaching the Hoses to the Test Points

1. As indicated above, use an appropriate fitting to connect the open end
of the High pressure (red) hose to the test point with the higher line
pressure.

2. Using an appropriate fitting, connect the open end of the Low pressure
(blue) hose to the test point with the lower line pressure.

NOT ICE

If the hoses are connected in the inverse orientation (i.e., High pressure
(red) hose to the lower line pressure), the displayed High-side gauge
pressure (High P) will be less than the Low-side gauge pressure (Low P),
and the Differential pressure (dP) will be negative.

P e r f o r m i n g P r e s s u r e M e a s u r e m e n t s

The HM675 Hydronic Manometer allows for simultaneous measurement
and display of the High-side gauge and Differential pressure. The
calculated Low-side gauge pressure is also displayed. The manometer
is equipped to make and display either discrete or continuous pressure
measurements.

Pressure Measurement Screen

*Shown with two optional accessory temperature probes attached.

2-8 Hydronic Manometer Model HM675

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

High-Side Gauge Pressure

The High-side gauge pressure
measurement is indicated as High on the
manometer display. The gauge pressure
readings can be positive or negative values
in the range of -20 to 300 psi (-138 to
2068 kPa).

Low-Side Gauge Pressure

The Low-side gauge pressure reading is
indicated as Low on the manometer
display. It represents a calculated value
determined from the measured High-side
gauge and Differential pressure as follows:

Low P = High P – dP

Differential Pressure

The Differential pressure measurement is
indicated as dP on the manometer display.
The differential pressure readings can be
positive or negative values in the range of
±300 psi (±2068 kPa).

Continuous Measurements

The HM675 Hydronic Manometer continuously measures and displays
pressure readings whenever the manometer is turned on, with the
exception of when the READ key is pressed. When the READ key is
pressed, the displayed readings are averaged measurements taken over
the sampling period as defined by the current time constant setting. The
display is updated once per second.

Discrete Pressure Measurements

Taking a discrete pressure measurement allows for measurement and
display of a single time-averaged reading taken over the sampling period
as defined by the current time constant setting. Discrete pressure
measurement values are displayed on-screen for a period of 10 seconds
and then returns to continuous measurement mode.

1. Press the READ key.

2. Allow the manometer to stand undisturbed until the reading is complete
(time of completion dependent on the time constant setting).

Find Quality Products Online at: [e-mail]

Instrument Operation 2-9

www.GlobalTestSupply.com

P e r f o r m i n g T e m p e r a t u r e M e a s u r e m e n t s

C A U T I O N S

• Exercise caution when disconnecting the HM675 Hydronic Manometer
from a pressurized system. Water or air discharged under pressure
poses a potential risk of severe injury.

• Exercise caution in using the HM675 Hydronic Manometer near
electrical equipment. Water spray associated with purging or
disconnecting hoses presents a potential risk of damage to such
equipment.

• Thoroughly drain and dry the HM675 Hydronic Manometer hoses and
internal piping after each use. This will help in limiting the potential for
growth of hazardous microorganisms.

The accessory temperature probe is an optional tool for the HM675
Hydronic Manometer. The 1/8” diameter, stainless steel sheathed
immersion probe is designed for measurement of water line
temperatures. When using the accessory temperature probe, the HM675
Hydronic Manometer is equipped to make and display either discrete or
continuous temperature measurements. Two temperature probes can be
connected to the instrument to measure upstream and downstream
temperature simultaneously.

Connecting the Temperature Probe

Connect the keyed 3-pin plug of the accessory temperature probe to the
mating connector located on the right-hand side of the manometer.

NOT ICE S

A locking nut is provided on the accessory temperature probe plug to allow
for a more secure attachment when connecting to the manometer.

When using the accessory temperature probe, the unit of measurement for
temperature (°F or °C) is driven by the selected unit of measurement for
differential pressure:

• Differential pressure in psi, inH2O, ftH2O, or inHg → temperature in °F

• Differential pressure in kPa, mH2O, mmHg, or bar → temperature in °C

D i s c o n n e c t i n g t h e M a n o m e t e r f r o m t h e T e s t P o i n t s

Find Quality Products Online at: [e-mail]

2-10 Hydronic Manometer Model HM675

The following provides a guideline for disconnecting the manometer from
the test points once measurements have been completed.

1. Turn the shut-off ball valve on both the High and Low pressure hoses
to the closed position.

www.GlobalTestSupply.com

2. Disconnect the High pressure (red) hose from the higher line pressure
test point.

3. Disconnect the Low pressure (blue) hose from the lower line pressure
test point.

NOT ICE

If additional measurements at another location/system containing the same
fluid are to be made, it is not necessary to proceed to step 4 and drain the
fluid entrained within the hoses at this time. The fluid remaining within the
hoses will help minimize the time necessary to bleed entrained air prior to
making subsequent measurements.

4. Place the open end of the Low pressure (blue) hose in a suitable
receptacle or near a drain.

5. Turn the valve handle on the manometer to the BYPASS position.

6. Turn the shut-off ball valve on the Low pressure (blue) hose to the
open position to discharge the pressurized fluid out of the open end of
the Low pressure (blue) hose.

7. Elevate the High pressure (red) hose and turn its shut-off ball valve to
the open position to allow for draining of the remaining entrained fluid.

Instrument Operation 2-11

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

C H A P T E R 3

M a i n t e n a n c e a n d
Troubl e s h o o t i n g

The HM675 Hydronic Manometer has been designed to provide long-term
field use with minimum required maintenance. As with any precision
electronic device, however, proper care, maintenance, and handling will
further ensure its accurate and reliable operation.

There are no user-serviceable parts inside this instrument. Opening the
instrument case may void the warranty. TSI® recommends that you
return the HM675 Hydronic Manometer to the factory for any required
maintenance or service not described in this manual.

R o u t i n e M a i n t e n a n c e

I M P O R T A N T

The following guidelines should be followed whenever storing the HM675
Hydronic Manometer:

Draining the Hoses

Fluid within the High (red) and Low (blue) pressure hoses should be
properly drained whenever the instrument is being stored after use.

1. Disconnect the manometer hoses from the test points (Reference

Chapter 2, "Disconnecting the Manometer from the Test Points").

2. Disconnect the High (red) and Low (blue) pressure hoses from the
manometer.

3. Turn the shut-off ball valve on both the High and Low pressure hoses
to the open position.

4. Using a suitable high pressure air source, blow the entrained liquid
from both hoses.

Draining the Manometer Valve

Fluid within the manometer valve should be properly drained whenever the
instrument is being stored after use.

1. Disconnect the High (red) and Low (blue) pressure hoses from the
manometer.

2. Turn the valve handle on the manometer to the BYPASS position.

3. Hold the manometer with the pressure ports directed downward to
allow liquid to drain from the unit.

3-1

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4. Turn the valve handle on the manometer to the MEASURE position.

Flow Restrictor

Shut-Off Valve

Short Hose Section

5. Hold the manometer with the pressure ports directed downward to
allow liquid to drain from the unit.

NOT ICE

The HM675 Hydronic Manometer should be stored with the valve handle in
the MEASURE position.

In-Line Flow Restrictor

The blue and red hose assemblies include flow restrictors. The flow
restrictors must be used to prevent damage to the pressure sensors from
unexpected water hammering or pressure spikes and also acts as a filter.

Do not use the HM675 Hydronic Manometer without the flow restrictors

installed in the hose assemblies or sensor damage or clogging will occur.

Cleaning the In-line Flow Restrictors

These flow restrictors should be flushed periodically with clean water to
minimize potential clogging.

1. Disconnect the hose from the manometer.

2. Turn the shut-off ball valve on the hose to the closed position.

3. Connect the straight female flare fitting (farthest from the hose shut-off
valve) on the hose to a suitable water source.

4. Place the open end of the hose in a suitable receptacle or near a drain.

5. Turn the shut-off ball valve on the hose to the open position and allow
water to flush through for several minutes.

6. Using a suitable high pressure air source, blow the entrained water
from the hose.

7. Repeat with the second hose.

NOT ICE

If necessary, remove the flow restrictor for further cleaning or flushing.
Reattach to hose assembly when complete.

3-2 Hydronic Manometer Model HM675

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

C a l i b r a t i o n

Cleaning the Instrument Housing

The HM675 Hydronic Manometer may be cleaned using a soft, damp,
clean cloth.

NOT ICE

DO NOT use solvents or abrasive cleaners to clean the instrument

housing, keypad, or display.

TSI® recommends that the HM675 Hydronic Manometer receive an annual
calibration. TSI® will verify calibration of the instrument and re-issue a
certificate of calibration with traceability to NIST. This “annual checkup”
helps to ensure the specified accuracy of the instrument is maintained.

To calibrate the instrument, please ship TSI® the complete package that
includes the meter and accessory temperature probe. Everything should be
packed carefully within the carrying case and then inside a shipping box.
The original shipping box and packaging (carton and foam) is preferred.

Before returning the Hydronic Manometer to TSI for service, visit our
website at for specific return instructions. Customer Service will need the
following information when you call:

• The instrument model number

• The instrument serial number

• A purchase order number (unless under warranty)

• A billing address

• A shipping address

(continued on next page)

Maintenance and Troubleshooting 3-3

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

T r o u b l e s h o o t i n g

Symptom

Possible Causes

Corrective Action

No display

Unit not turned on.

Low or dead batteries.

Dirty battery contacts.

AC adapter not connected.

Press On/OFF key.

Replace or recharge the batteries.

Clean the battery contacts.

Plug in AC adapter.

“ “
flashing on display

Low battery charge.

Dirty battery contacts.

Replace or recharge the batteries.

Clean the battery contacts.

“8888”
flashing on display

The indicated measurement is
out of range.

The allowable ranges for pressure and
temperature measurements are shown on
the specifications page.

“-----”
on display

The temperature sensor is
unplugged

The pressure measurement is
out of the meter’s range.

Try one of the below two steps:

1. Plug in temperature probe.

2. Return the pressure measurement to
the correct range

Instrument
unresponsive to
pressure

Hoses are clogged

Make sure hoses and flow restrictors are
unclogged from any debris by following
instructions on Cleaning the In-line Flow

Restrictors.

Error Message

Possible Causes & Corrective Action

"Saved Pressure Zero”

There was a problem with a pressure zero reading read from
memory. Differential pressure and gauge pressure should both be
re-zeroed.

The following table lists the symptoms, possible causes, and
recommended solutions for common problems encountered with the
instrument. If your symptom is not listed, or if the recommended solutions
do not address your problem, please contact the factory.

The following table lists error messages which can be displayed should the
instrument detect a problem. Should any of these error messages recur
repeatedly, the instrument should be returned to the factory for servicing.

Find Quality Products Online at: [e-mail]

3-4 Hydronic Manometer Model HM675

www.GlobalTestSupply.com

A P P E N D I X A

Range

Differential Pressure ................

Gauge Pressure ......................

Operating Temperature ...........

Storage Temperature ..............

Temperature Probe .................

Liquid Media ............................

±300 psi (±2068 kPa)

-20 to 300 psi (-138 to 2068 kPa)
(-40 to 610 in.Hg)

40 to 113°F (5 to 45°C) electronics

-4 to 140°F (-20 to 60°C)

-40 to 250°F (-40 to 121°C)
32 to 180°F (0 to 82°C)

Resolution

Pressure (best) ........................

Temperature ............................

0.001 psi (0.01 kPa) (0.01 in. Hg)

0.1°F (0.1°C)

Accuracy

Pressure1 .................................

Temperature ............................

±1% of reading +.072 psi (0.5 kPa)
(0.15 in.Hg)

±0.5% of reading +1.2°F (0.7°C)

Units

Pressure ..................................

Temperature ............................

psi, in. H2O, ft H2O, kPa, mm Hg, in. Hg,
m H2O, bar

degrees F, degrees C

Time Constant ........................

user selectable (1, 5, 10, 20, and 30
seconds)

Display ....................................

LCD with backlight

Dimensions (meter only) ........

11.1 in. × 4.7 in. × 3.5 in.
(28.2 cm × 11.9 cm × 8.8 cm)

Pressure Connection ............

¼” 37° Flare Fitting, Male

Weight with Batteries ............

2.65 lb. (1.20 kg)

Power Requirements .............

four AA-size cells, alkaline or
rechargeable NiMH (included), or AC
adapter (included) 9 VDC, 2 A, regulated

Battery Life2 ............................

minimum of 12 hours with backlight on
minimum of 18 hours with backlight off

Recharge Time .......................

4 hours (internal charger)

Warranty .................................

2-year factory warranty

Specificati o n s

Model HM675 Hydronic Manometer specifications are as follows

(specifications are subject to change without notice).

1

Accuracy statement applies from -15 to 250 psi (-103 to 1724 kPa).

2

The minimum battery life stated will occur after the NiMH batteries have been recharged

2 to 3 times after initial charge.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

A-1

CE Marking

EN61326 / EN 55011, Class B: Radiated Emissions
EN61326 / EN 55011, Class B: Conducted Emissions
EN61000-4-2: Electrostatic Discharge Immunity
EN61000-4-3: Electromagnetic Field Immunity
EN61000-4-4: Burst Immunity
EN61000-4-5: Surge Immunity
EN61000-4-6: Conducted PS Immunity
EN61000-4-8: Rated Power-Frequency Field Immunity
EN61000-4-11: Voltage Dips\Short Interruptions Immunity

RoHS Marking

Yes

A P P E N D I X B

C o m p l i a n c e

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

B-1