Uson 628 User manual

Document No. 690020 - Rev.3.0
Operator’s Manual

Portions of the software are copyright © 2017 Uson, L.P. and
copyright © 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
Product or trade names mentioned in this manual may be trademarks or
registered trademarks of their respective companies.
USON L.P. makes no representations or warranties with respect to the
contents or use of this manual and specifically disclaims any
express or implied warranties of merchantability or fitness for any purpose.
Uson has made every attempt to completely describe the operation of the
tester. Uson shall not be liable for technical or editorial errors or
omissions. USON L.P. reserves the right to revise this manual and to make
changes to its content, at any time, without obligation to notify any person
or entity of such revisions or changes.
This manual copyright © 2017 Uson L.P.
All rights reserved. Printed in the U.S.A.
Published by Uson L.P.
8640 North Eldridge Parkway
Houston, Texas 77041
U.S.A.
[phone]
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Mail: [e-mail]
www.uson.com
Customer Support Hotline: [phone]
Sales and Support Offices
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77014 
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Website:www.uson.com Website:www.uson.com Website:www.uson.com Website:www.uson.com

Contents i
Contents
Chapter 1: Safety 1-1
Introduction......................................................................................................................1-1
Using this Manual......................................................................................................1-1
Safety Alert Symbols ................................................................................................1-1
Safety Precautions (English)............................................................................................1-2
WEEE Material Disposal.................................................................................................1-3
Abbreviations...................................................................................................................1-4
EU Declaration of Conformity ........................................................................................1-5
China RoHS Declaration .................................................................................................1-6
Chapter 2: Introduction 2-1
Uson 628 Overview .........................................................................................................2-1
Specifications...................................................................................................................2-3
Front Panel Overview ......................................................................................................2-6
Front Panel.................................................................................................................2-6
Pneumatic Configuration .................................................................................................2-7
Component Operation................................................................................................2-8
Leak Test Cycle .........................................................................................................2-9
Chapter 3: Installation/Wiring 3-1
Installation .......................................................................................................................3-1
Unpacking .................................................................................................................3-1
Location .....................................................................................................................3-1
Wiring/Connections .........................................................................................................3-2
Rear Panel ..................................................................................................................3-2
Power Supply.............................................................................................................3-4
Power Supply Specifications ...............................................................................3-5
Connections .........................................................................................................3-5
Pneumatic Connections..............................................................................................3-6
Serial port connection ................................................................................................3-7
I/O Connector E .........................................................................................................3-7
Isolated Power Supply .........................................................................................3-8
Result & Ready Outputs ......................................................................................3-8
Start/Reset/Enable Inputs.....................................................................................3-9
Program Selection..............................................................................................3-10
Alarm/ End-of-Cycle Outputs............................................................................3-12

ii Uson 628 Operator’s Manual
Chapter 4: Getting Started 4-1
Introduction......................................................................................................................4-1
Turning the Tester On/Off ...............................................................................................4-2
Menu Navigation .............................................................................................................4-3
Front Panel Controls ..................................................................................................4-3
Key Pad......................................................................................................................4-3
Menu Toolbars...........................................................................................................4-4
Data............................................................................................................................4-4
Menu Selection ..........................................................................................................4-5
Parameter Entry Screen .............................................................................................4-5
Selection List Entry .............................................................................................4-6
Text Entry ............................................................................................................4-6
Numeric Entry......................................................................................................4-7
Logs Review ........................................................................................................4-7
Password Overview .......................................................................................................4-11
Setting a Password .........................................................................................................4-12
Password entry.........................................................................................................4-13
Forgot Password ......................................................................................................4-13
Menu Item Access Control ............................................................................................4-14
Chapter 5: Program Mode 5-1
Introduction......................................................................................................................5-1
Entering Program Mode...................................................................................................5-1
Program Categories..........................................................................................................5-2
Program Menu (submenus)........................................................................................5-3
Comp/Cal Menu.........................................................................................................5-6
Linking Menu ............................................................................................................5-6
Data Menu..................................................................................................................5-7
Date Time Menu ........................................................................................................5-8
Set Up Menu ..............................................................................................................5-8
Config Menu ............................................................................................................5-10
Gauge Sensor ...........................................................................................................5-10
Differential Sensor...................................................................................................5-11
Regulator Menu .......................................................................................................5-12
Hardware Menu .......................................................................................................5-12
Chapter 6: Run Mode 6-1
Overview..........................................................................................................................6-1
Operations..................................................................................................................6-1

Contents iii
Chapter 7: How To 7-1
Program Basic Test Parameters .......................................................................................7-1
Preliminary Tasks ......................................................................................................7-1
Set Pressure Units ......................................................................................................7-2
Set Test Program Details ...........................................................................................7-3
Perform a Test..................................................................................................................7-4
Test Results................................................................................................................7-7
Lamp Outputs ............................................................................................................7-8
Audit Results Output .................................................................................................7-8
Optimize a Program .........................................................................................................7-9
Fill Time ....................................................................................................................7-9
Stabilize Time ............................................................................................................7-9
Measure Time ............................................................................................................7-9
Reject Level .............................................................................................................7-10
Program Linking ............................................................................................................7-11
Program Linking Features .......................................................................................7-11
Fast Fill ..........................................................................................................................7-12
Chapter 8: Leak Calibration (Comp/Cal) 8-1
Overview..........................................................................................................................8-1
Performing a Leak Rate Calibration ................................................................................8-3
Calibration Test Program Setup.................................................................................8-3
Comp Test............................................................................................................8-3
Cal Test ................................................................................................................8-4
Chapter 9: Maintenance 9-1
Routine Maintenance .......................................................................................................9-1
Daily...........................................................................................................................9-1
Weekly .......................................................................................................................9-1
Cleaning ...........................................................................................................................9-1
Preventive Maintenance...................................................................................................9-2
Fuse Replacement ............................................................................................................9-2
Functional Check .............................................................................................................9-3
Introduction................................................................................................................9-3
Leak Tightness Test ...................................................................................................9-3
Leak Comparison Test .........................................................................................9-3
Software Update ..............................................................................................................9-4

iv Uson 628 Operator’s Manual
Chapter 10: Spares/Accessories 10-1
Spares.............................................................................................................................10-1
Accessories ....................................................................................................................10-2
Chapter 11: Appendix A -Sample Reports 11-1
Sample Reports ..............................................................................................................11-1

1
Chapter 1Preface
Please read this Operating Manual carefully before putting your 628 into service,
especially all safety related WARNINGS and CAUTIONS throughout the
manual.
About this manual
The purpose of this manual is to inform the operator how to connect, wire, operate,
maintain, and troubleshoot the 628 Tester.
Intended Use
This tester is intended to be used in an indoor, industrial environment by suitably
trained personnel.
Equipment Needed
• Master Part-Must be a known good part and be identical and of same material
as production parts (for calibration).
• Leak Master (for calibration).
Document History
• 11-30 -2017:Revision 1.0. Initial release.
• 03-01-2019: Revision 2.0. Added Electronic Regulator, Second fill step,
Program Linking option details (Software version 1.0.5).
• 03-08-2021: Revision 3.0 General improvements and corrections (Software
version 1.0.9).

Safety 1-1
1
Chapter 1Safety
1.1 Introduction
This section explains the warnings and cautions that should be observed before
using, wiring, installing, or operating the Uson 628.
Safety information is covered at relevant points throughout the manual. Please
read this manual in its entirety before installing/wiring or operating the instrument.
Should any point remain unclear, contact your supplier for assistance before
proceeding.
This tester is intended to be used in an industrial environment by suitably trained
personnel.
1.1.1 Using this Manual
The instructions in this manual are intended to assist qualified personnel for
correct installation, wiring, operating, adjusting, servicing, maintaining, and
troubleshooting of this tester.
1.1.2 Safety Alert Symbols
WARNING: Informs users of potentially hazardous situation, such as
personal injury or death and/or severe equipment damage, if instructions are
not followed.
CAUTION: Informs user of potential hazards to equipment if instructions are not
followed and may invalidate the warranty.
NOTE: Helps user perform task.

1-2 Uson 628 Operator’s Manual
1.2 Safety Precautions (English)
Electrical and Pneumatic (or air pressure) hazards are two primary concerns when
operating the Uson 628. Observe the following safety precautions before using this
product or associated equipment.
WARNING: If the equipment is used in a manner not specified in this manual,
the protection provided by the equipment may be impaired.

WARNING: Avoid Personal injury and/or Equipment Damage. Tested parts
must be secured in place mechanically or be enclosed/covered to avoid
personal injury or equipment damage. Securing tested parts with air couple
devices only, is NOT sufficient. Loss of power or air pressure, or multiple
reset/abort inputs while the vent step is running will immediately de-energize
any couple/clamp valves
WARNING: This instrument is capable of supplying high-pressure air. Before
commencing any component tests, ensure that the system is guarded to local
health and safety standards.
WARNING: Always wear eye protection when working with pressurized air.
Disconnect all pressure sources when working with internal components of
Uson equipment:
WARNING: The component to be tested, and the air supply line to the Uson
628, must be free from water or liquid residue before testing; otherwise
damage may be inflicted on the sensitive transducer within the instrument.
WARNING: Uson 628 operates on 24VDC from a power supply supplied by
Uson, which must be connected to an earthed (grounded) power supply of 
100-240VAC 50/60Hz.
WARNING:.The covers on the equipment should be removed only by
personnel trained to avoid the risk of electric shock. The power supply to the
equipment must be switched off and disconnected before removing any
covers.

Safety 1-3
1.3 WEEE Material Disposal
Uson is committed to meeting the requirements of the European Union (EU) Waste
Electrical and Electronic Equipment (WEEE) Directive. Uson products that are
within the scope of the Directive are labelled with a crossed-out "wheelie-bin"
symbol, as required by the Directive. It indicates that the product was placed on the
market after August 13, 2005 and that end users should segregate the product from
other waste at end-of- life.
The detailed requirements vary considerably throughout the EU, and the Uson
WEEE compliance approach varies among countries.
WARNING: Do not substitute the fuse rating. Always use the correctly rated
fuse, failure to do so may be hazardous and can cause damage to the
equipment.
WARNING: Do not make or break external connectors or connections while
the Uson 628 is switched on.

1-4 Uson 628 Operator’s Manual
1.4 Abbreviations
Abbreviation Definition
RTC Real Time Clock
BCD Binary Coded Decimal
LVD Low Voltage Directive
EU European Union
EMC Electromagnetic Compatibility
RHOS Restriction of Hazardous Substances
I/O Input/Output
EOC End of Cycle
DC Direct Current
SC Sealed Component.
REF Reference
USB Universal Serial Bus
PLC Programmable Logic Controller
ISO Isolated
FAT File Allocation Table
ADC Analogue to Digital Convertor

Safety 1-5

1-6 Uson 628 Operator’s Manual
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Introduction 2-1
2
Chapter 2Introduction
2.1 Uson 628 Overview
The Uson 628 is a differential pressure decay tester that is easily configurable to
test a wide range of components using the Differential Pressure Decay method.
The tester uses the highly sensitive and reliable Uson differential pressure
transducer to measure leak rate within a test component.
For normal operation, the operator simply connects the component to the tester’s
test port and then presses Start. The Tester determines the leak rate within a test
component by pressurizing the component and measuring any pressure variation
between the component and a reference volume, using a differential pressure
transducer. A pass or reject result is indicated on the front panel LEDs and the leak
measurement is displayed on the front panel display.
The programs can be configured from the front panel using seven tactile keys,
making it simple to operate. The programs are stored, to enable tests to be selected
and run by an operator without knowledge of the programming procedure.
Features:
• Simple menus
• Differential pressure drop measurement
• Pressure or Vacuum versions available
• Manual or Electric Pressure Regulation.
• 30 programs
• Statistics can be displayed or printed
• Date and time facilities
• Program copy
• Data transfer by USB memory device
.

2-2 Uson 628 Operator’s Manual
Applications
The testers can be used in almost any leak testing application, some typical
examples are:
Typical Applications
Water Pumps Medical Tube Sets
Heat Exchangers Bottle Tests
Fuel Pumps Blood Bags / Ostomy Pouches
Steering Racks Domestic Appliances
Hydraulic Components Packaging
Valves Castings
Combustion Chambers Pressure Switches

Introduction 2-3
2.2 Specifications
Model
Uson 628
Description: Differential Pressure Decay Tester
Regulator
Manual or Electronic
Differential Sensor
Sensor Type: Capacitive differential pressure sensor
Resolution: 0.0001 psi, 0.01 mbar, 1 Pa .
Range:
0 to 0.3psi, 0 to 20mbar, 0 to 2000 Pa.
Accuracy: ±1% of full scale range
Gauge Sensor
Sensor Type: Solid State Sensor
Range:
0 to -14.5 psi, 0 to -1.00 bar, 0 to -100 kPa
0 to 15 psi, 0 to 1 bar, 0 to 100 kPa
0 to 60 psi, 0 to 4 bar, 0 to 400 kPa
0 to 150 psi, 0 to 10 bar, 0 to 1 MPa
0 to 225 psi, 0 to 15 bar, 0 to 15 MPa
Accuracy: ±1% of Gauge pressure range
Step times:
0.0 to 5000.0 s
Measure time:
0.1 to 5000.0 s
Reject Level:
Adjustable down to 0.5% of range.
Statistics:
Pass, Reject, Abort, and Total Counters. Min,
Max, Av.Pass, Av.Reject values
Programs:
30 test programs.
Dimensions:
(HWD) 150.9mm x 331.4 mm x 450.4 mm
(5.94” x 13.05” x 17.73”)
Weight:
10kg / 22 lb.
Interfaces
RS232, USB, PLC I/O Control
Pressure
Units
psig, bar, mbar, Pa, kPa, kg/cm², mmH2O,
cmH20, inH2O, mmHg, cmHg inHg
Operating
Temperature:
5°C to 40°C (41°F to 104°F)

2-4 Uson 628 Operator’s Manual
Input Power
Requirement:
24 Volt DC 1.5A, 36W
Fuse Rating:
T5.0A/250V, 20mm Glass Fuse
Pneumatic
Supply:
Clean, dry air, 5 to 16 bar. Particulate matter
<25 microns Dew point 17
º C, Oil mist
<0.1mg/m3
Couple Port
Output pressure 5 bar ±0.5 bar.
Serial Port: Baud rate; 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200
Parity; none, odd, even 
Data Bits; 7, 8
Control; none, RTS/CTS
USON reserves the right to change the specification without notice.

Introduction 2-5
Figure 2–1: 628 Overall Dimensions

2-6 Uson 628 Operator’s Manual
2.3 Front Panel Overview
2.3.1 Front Panel
Figure 2–2 shows the Uson 628’s front panel controls/connections, while 
Table 2–1 describes their functions.
Figure 2–2: Uson 628 Front Panel Overview
Table 2–1: Uson 628 Front Panel Descriptions
Item# Connection/Control Description
1Start Button
Starts a test cycle or updates the selected value when
editing parameters.
2 Abort Button
Resets or aborts a test cycle or reverts the selected value
when editing parameters.
3 Left/Right Keys Selects the next or previous displayed parameter.
4 Function Keys Functions available for the displayed menu or parameter.
5Display
A character Liquid Crystal Display (LCD) that displays the
tester’s state, function, mode, and parameter settings.
6 Result Indicator Test cycle pass and reject indicators, On or Off.
7 Calibration Port
Used to connect a standard leak or calibration instrument
to the test circuit for calibration.

Introduction 2-7
2.4 Pneumatic Configuration
The Uson 628 employs two pneumatically controlled valves to supply compressed
air (or other gas) for leak testing a component.
The valves operate in a programmed sequence, to pressurize a test component and
a reference component or chamber. The test and reference components are then
isolated from each other and a differential transducer is used to monitor the
pressure difference between the two ports.
A leak in the test component results in a pressure change, which is used to decide
whether a leak in the test component is within a specified tolerance.
Figure 2–3: Pneumatic Configuration