Sartorius arium mini plus User manual

Operating Instructions
Original Operating Instructions
Arium®Mini Plus | Arium®Mini |
Arium®MiniEssential
H2O-MA-… | H2O-MM-… | H2O-MU-…
Ultrapure Water System
1000025355

Contents
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 3
Contents
1 About this Document .............................. 5
1.1 Validity........................................ 5
1.2 Symbols Used................................. 5
1.2.1 Warnings in Action Descriptions ...... 5
1.2.2 Other Symbols ........................ 5
2 Safety Notes.........................................6
2.1 Intended Use ..................................6
2.2 Personnel Qualification........................6
2.3 Significance of These Instructions .............7
2.4 Functionality of the Device ....................7
2.5 Electrical Equipment ..........................8
2.5.1 Damage to the Electrical Equipment
of the Device ...........................8
2.5.2 Working on the Electrical Equipment
of the Device ...........................8
2.5.3 Power Supply and Power Cord .........8
2.6 Accessories, Consumables and Spare Parts ...8
3 Device Description ..................................9
3.1 Device Overview...............................9
3.2 Electrical Connections....................... 10
3.3 Water Connections .......................... 10
3.4 Tubing ........................................11
3.4.1 Feed WaterTubing ....................11
3.4.2 Tank Filling Tubing.....................11
3.4.3 Drain Water Tubing....................11
3.4.4 Tank Outlet Tubing with Ball Cock ....11
3.4.5 Dispense Tube.........................11
3.5 Ultrapure Water Treatment . . . . . . . . . . . . . . . . . . .12
3.5.1 System Setup..........................12
3.5.2 Feed Water Intake.....................13
3.5.3 Treatment Stages......................13
3.5.4 Final Purification Stage................14
3.5.5 Circulation of the Ultrapure Water ....14
4 Operating Design ..................................15
4.1 Menu .........................................15
4.2 Dispensing Mode .............................16
4.3 Message Display..............................17
4.4 Messages in Dispensing Mode ...............18
4.5 Message List..................................19
4.6 Numeric Keypad.............................20
4.7 Navigating the Menus ........................21
4.8 Menu Structure..............................22
4.9 Parameters of the “Settings” Menu ..........24
5 Installation.........................................26
5.1 Equipment Supplied.........................26
5.2 Prerequisites for Installation at the
Installation Location ......................... 27
5.3 Unpacking and Setting up the Device . . . . . . . 27
5.3.1 Removing the Left Side Cover .......28
5.3.2 Removing Parts ......................28
6 Startup.............................................29
6.1 Connecting the AC Adapter .................29
6.2 Configuring Device Settings (Startup).......30
6.2.1 Setting the Language ................30
6.2.2 Launching Startup Mode.............30
6.2.3 Setting the Date and Time.............31
6.2.4 Setting the Displayed Values ..........31
6.2.5 Concluding Device Settings
(Startup)..............................32
6.3 Inserting Pretreatment Cartridge
(onlyArium®Mini Plus) ......................32
6.4 Inserting Ultrapure Water Cartridge.........33
6.5 Inserting Bag (onlyArium® Mini Plus or
Arium®Mini) .................................34
6.6 Connecting Tubing ..........................35
6.6.1 Connecting Feed WaterTubing
(onlyArium®Mini Plus or
Arium®Mini)..........................35
6.6.2 Connecting Tank Filling Tubing
(onlyArium®Mini) ....................36
6.6.3 Connecting Drain WaterTubing
(onlyArium®Mini Plus or
Arium®Mini)..........................37
6.6.4 Connecting the Tank Outlet Tubing
(onlyArium®MiniPlus or
Arium® Mini) ..........................38
6.7 Rinsing Pretreatment Cartridge
(onlyArium®Mini Plus).......................39
6.8 Rinsing the Ultrapure Water Cartridge ......40
6.8.1 Filling of the Bag
(onlyArium® Mini Plus and
Arium®Mini)..........................40
6.8.2 Performing a Rinse Cycle..............41
6.8.3 Re-filling the Bag During the Rinse
Cycle (onlyArium®Mini) .............42
6.8.4 Completing the Rinsing Process .....42
6.9 Connecting the Final Filter ..................43
6.10 Rinsing the Final Filter . . . . . . . . . . . . . . . . . . . . . . . 43

Contents
4 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
7 Operation .........................................44
7.1 Switching the Device On and Off............44
7.2 Dispensing Ultrapure Water .................44
7.2.1 Preparing to Dispense Ultrapure
Water.................................44
7.2.2 Dispensing Ultrapure Water
Manually .............................45
7.2.3 Dispensing Ultrapure Water with
Volume-control ......................46
7.2.4 Confirming Dispensing
Cancellation..........................47
7.2.5 Ending the Dispensing via the
Dispense Tube........................47
7.2.6 Dispensing Ultrapure Water From
the Bag (Only With Arium®Mini Plus
orArium®Mini) .......................48
7.3 Opening the Menu ..........................48
7.4 Manually Fill the Bag
(Only forArium®Mini) .......................49
7.4.1 Starting Manual Filling via the
Wizard................................49
7.4.2 Starting Manual Filling in Menu ......49
7.5 Activating or Deactivating Standby Mode ....51
7.5.1 Automatic ECO Mode ................51
7.6 Changing System Settings....................51
7.7 Performing a Volume Adjustment ...........52
8 Cleaning and Maintenance........................53
8.1 Cleaning .....................................53
8.1.1 Cleaning the Display .................53
8.1.2 Cleaning the Device Housing ........53
8.2 Maintenance Schedule ......................54
8.3 Opening the “Care” Menu ...................54
8.4 Displaying Reminders........................55
8.5 Replacing Consumables.....................55
8.5.1 Selecting Consumables for
Replacement .........................55
8.5.2 Replacing Bag
(onlyArium®Mini Plus or
Arium®Mini)..........................56
8.5.3 Replacing Pretreatment Cartridge
(onlyArium®MiniPlus) ...............57
8.5.4 Replacing Ultrapure Water
Cartridge .............................58
8.5.5 Replacing the UV Lamp ..............59
8.5.6 Changing Final Filter .................62
8.6 Enabling, Disabling or Configuring
Reminders for Replacing Final Filters........63
8.7 Carrying Out Depressurization ..............63
8.8 Carrying Out Venting........................64
8.9 Performing the Final Rinsing Procedure.....65
9 Malfunctions ......................................66
9.1 Error Messages ..............................66
9.2 Warning Messages ..........................69
9.3 Additional Faults..............................71
10 Storage and Shipping.............................. 72
10.1 Storage ...................................... 72
10.2 Returning Device and Parts.................. 72
11 Decommissioning .................................73
12 Transport ..........................................73
12.1 Transporting the Device ..................... 73
13 Disposal............................................74
13.1 Information on Decontamination............74
13.2 Disposing of Device and Parts ...............74
13.2.1 Information on Disposal..............74
13.2.2 Disposal ..............................75
14 Technical Specifications...........................76
14.1 Power Supply ................................76
14.2 Ambient Conditions .........................76
14.3 Safety of Electrical Equipment................77
14.4 Electromagnetic Compatibility ...............77
14.5 Product Water Quality.......................78
14.5.1 Arium®Mini Plus .....................78
14.5.2 Arium®Mini and
Arium® Mini Essential ................79
14.6 Feed Water Quality ..........................79
14.6.1 Arium®Mini Plus .....................79
14.6.2 Arium®Mini ..........................80
14.6.3 Arium® Mini Essential ................80
14.7 Device Properties............................80
15 Consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
16 Sartorius Service....................................81
17 Conformity ........................................82
17.1 EC / EU Declaration of Conformity ..........82
17.2 FCC Supplier’s Declaration of Conformity...82
17.3 UK Declaration of Conformity ...............82
17.4 CSA Declaration of Conformity..............82

About this Document
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 5
1 About this Document
1.1 Validity
These instructions are part of the device. These instructions apply to the
device in the following versions:
Device Model name
Arium®Mini Plus H2O-MA-UV-T|H2O-MA-T|H2O-MA-UV-T-US|
H2O-MA-T-US
Arium®Mini H2O-MM-UV-T|H2O-MM-T|H2O-MM-UV-T-US|
H2O-MM-T-US
Arium® Mini Essential H2O-MU-UV-T|H2O-MU-T|H2O-MU-UV-T-US|
H2O-MU-T-US
1.2 Symbols Used
1.2.1 Warnings in Action Descriptions
WARNING
Denotes a hazard that may result in death or serious injury if it is not
avoided.
CAUTION
Denotes a hazard that may result in moderate or minor injury if not avoided.
NOTICE
Denotes a hazard that may result in property damage if it is not avoided.
1.2.2 Other Symbols
tRequired action: Describes activities that must be performed.
yResult: Describes the result of the activities carried out.
[ ] Text inside brackets refers to control and display elements.
Figures on the Operating Display
Depending on the device configuration, the figures depicting the device
and operating display may differ slightly from the supplied device. The
variants shown in these instructions are examples.

Safety Notes
6 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
2 Safety Notes
2.1 Intended Use
The device is a water purification system that produces “ASTM Type 1”
ultrapure water for daily requirements of up to 10 liters.
The device is intended exclusively for use in accordance with these
instructions. Any further use beyond this is considered improper.
If the device is not used properly:The protective systems of the device may
be impaired. This can lead to unforeseeable personal injury or property
damage.
Operating Conditions for the Device
Do not use this device in potentially explosive environments. The device
may only be used indoors.
The device may only be used with the equipment and under the operating
conditions described in the Technical Data of these instructions.
Modifications of the Equipment
You may not modify the device or make any technical changes on your own.
Any retrofitting or technical changes to the device are only permitted with
prior written permission by Sartorius.
Foreseeable Misuse
Using the device is only safe when it is operated in accordance with its
intended use.The following applications, for example, are not permitted:
— Operation outside the permissible ambient conditions
(see Chapter “14.2 Ambient Conditions,” page 76) e.g. extreme
temperatures, chemical vapors, moisture, shock, vibration or strong
electromagnetic fields
— Carrying out unauthorized modifications or other technical changes
onthe device
— Connecting unsuitable devices
— Installation of unauthorized items on or in the device
2.2 Personnel Qualification
These instructions are addressed to the target groups mentioned below.
Allpersons working on the device must possess the stated knowledge and
authorizations.
If no qualifications are indicated for the actions described in these
instructions: The actions described are addressed to the “user” target group.
If individual actions must be carried out by other target groups or by
Sartorius Service personnel: The qualification required will be indicated
inthe description of the action.

Safety Notes
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 7
Target group Knowledge / responsibilities
User The user is familiar with the operation of the device
and the associated work processes. He knows the
dangers that can occurwhen working with the
device and can avoid these dangers.
The user has been trained in the operation of the
device.
The training is carried out by the operating
engineer / laboratory manager or the operator
ofthe device.
Operating
engineer /
laboratory
manager
The operating engineer / laboratory manager
makes decisions about the use and
parameterization of the device.
The operating engineer / laboratory manager
istrained in the operation of the device.
Thetraining is performed by Sartorius Service
orthe operator.
Operator The operator of the device is responsible for
compliance with safety requirements and
workplace safety regulations.
The operator must ensure that all persons who
work with the device have access to the relevant
information and have been instructed in work with
the device.
2.3 Significance of These Instructions
Failure to follow these instructions can have serious consequences,
e.g.exposure of individuals to electrical, mechanical or chemical hazards.
t Before working with the device: Read the instructions carefully and
completely.
t If the instructions are lost: Request a replacement or download the latest
instructions from the Sartorius website (www.sartorius.com).
t The information contained in these instructions must be made available
to all individuals working with the device.
2.4 Functionality of the Device
A damaged device orworn parts may lead to malfunctions or cause hazards
which are difficult to recognize.
t Only operate the device when it is in proper working order.
t Complywith the maintenance intervals (for intervals and maintenance
tasks, see Chapter “8.2 Maintenance Schedule,” page 54).
t Have any damage repaired immediately by Sartorius Service.

Safety Notes
8 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
2.5 Electrical Equipment
2.5.1 Damage to the Electrical Equipment of the Device
Damage to the electrical equipment of the device, e.g. damage to the
insulation, can be life-threatening. Contact with parts under voltage
represents a direct danger to life.
t If the electrical equipment of the device is defective, immediately switch
off the power supply and contact Sartorius Service.
t Keep live parts away from moisture. Moisture can cause short circuits.
t Make sure that the power connection is equipped with a ground lead.
2.5.2 Working on the Electrical Equipment of the Device
Any work on or modifications to the electrical equipment of the device may
only be carried out by Sartorius Service personnel. The device may only
beopened by Sartorius Service personnel.
2.5.3 Power Supply and Power Cord
Serious injury can result, e.g. from electric shocks, if an unsuitable power
supply or an unsuitable / inadequately dimensioned power cords is used.
t Use only original power supplies and original power cords.
t Do not use inadequately dimensioned power cords.
t If the power supply or the power cord must be replaced:
ContactSartorius Service. Do not repair or modify the power supply
orpower cord.
2.6 Accessories, Consumables and Spare Parts
The use of unsuitable accessories, consumables and spare parts can affect
the functionality of the device, be hazardous and have the following
consequences:
— Risk of injury to persons
— Damage to the device
— Malfunctions of the device
— Total failure of the device
t Only use accessories, consumables and spare parts from Sartorius.
Sartorius can provide information on operational quality upon request.
t Only use accessories, consumables and spare parts that are in technically
perfect condition.

Device Description
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 9
3 Device Description
3.1 Device Overview
5
1
2
4
3
Fig.1: Arium®Mini Plus (example)
No. Description
1 Displaywith touch function
2 Water outlet
3 Final filter
4 Front cover
5 Side cover

Device Description
10 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
3.2 Electrical Connections
1
2
Fig.2: Electrical connections on the Arium®Mini Plus (example)
No. Description Explanation
1 “USB” connection For Sartorius Service
2 “Power” connection For connection of the AC adapter
(power supply)
3.3 Water Connections
1 2 3
Fig.3: Water connections on the Arium®Mini Plus (example)
No. Description Explanation
1 “Inlet” connection For connecting the tank filling tubing
orfeed water tubing
2 “Drain” connection For connecting the waste water tubing
(onlyArium®Mini Plus and Arium®Mini)
3 “Bag Outlet”
connection
For connecting the tank outlet tubing
(onlyArium®Mini Plus and Arium®Mini)

Device Description
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 11
3.4 Tubing
3.4.1 Feed Water Tubing
The feed water tubing is used to supply feed water to the device:
— Arium®Mini Plus: Supply of tap water
— Arium® Mini Essential: Supply of pretreated water
The feed water tubing is marked “Inlet”.
3.4.2 Tank Filling Tubing
The tank filling tubing serves to feed pretreated water from an external tank
to the device (onlyArium®Mini).
The tank filling tubing is marked “Inlet”.
3.4.3 Drain Water Tubing
The drain water tubing is used to drain unpurified water and rinse water out
of the device.
The drain water tubing is marked “Drain”.
3.4.4 Tank Outlet Tubing with Ball Cock
Pure water can be dispensed without pressure directly from the bag via the
tank outlet tubing with ball cock. This option can be used to empty the bag
when performing maintenance or to dispense pretreated water directly from
the bag for further use.
The tank outlet tubing is marked “Bag Outlet”.
3.4.5 Dispense Tube
The dispense tube is used for rinsing functions during startup and
maintenance as well as when dispensing larger volumes of water.

Device Description
12 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
3.5 Ultrapure WaterTreatment
3.5.1 System Setup
1 2 3 4 5 6 7 8 9 10
11
Fig.4: Arium®Mini Plus system setup
1 2 5 6 7 8 9 10
11
Fig.5: Arium®Mini system setup
1 6 7 8 910
Fig.6: Arium® Mini Essential system setup

Device Description
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 13
No. Description No. Description
1Inlet (feed water) 7UV lamp (185/254 nm)
2 Pump 8 Ultrapure water cartridge
(Scientific Pack)
3 Pretreatment cartridge 9 Conductivity measurement
4 Conductivity
measurement
10 Product water outlet
5 Bag 11 Outlet (drain water)
6 Pump
3.5.2 Feed Water Intake
The feed water intake differs according to the device type:
Device type Feed water intake
Arium®Mini Plus Direct connection to tap water connection
possible, automatic filling of the bag
Arium®Mini Manual filling of the bag with pretreated water
Arium® Mini Essential Direct connection to pretreated water
3.5.3 Treatment Stages
Device type Required treatment stages
Arium®Mini Plus Pretreatment stage, ultrapure water stage
Arium®Mini Ultrapure water stage
Arium® Mini Essential Ultrapure water stage
Pretreatment level (first treatment stage)
In the first treatment stage, the tap water is treated with pretreated water:
The feed water is passed through the pretreatment cartridge by means
ofamembrane pump. The pretreatment cartridge contains a combination
of activated carbon, catalyst and downstream reverse osmosis.
Thepretreatment cartridge removes particles, salts and impurities,
e.g.chlorine, from the tap water.
A large proportion of the impurities are discarded by means of
aconcentrate outlet (drainage water outlet).
The treated water is stored in the bag for further use. The quality of the
treated water is monitored via a conductivity measuring cell (LFR).

Device Description
14 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
Ultrapure water stage (second treatment stage)
In the second treatment stage, the pretreated water is purified to ultrapure
water (ASTM type 1): The pretreated water stored in the bag
(Arium®MiniPlus and Arium®Mini) or directly fed pretreated water
(Arium®Mini Essential) is fed into the ultrapure water circuit.
The water fed in can be freed from organic residues using an optional UV
lamp (185/254 nm). The pretreated water is then treated using the ultrapure
water cartridge (Scientific Pack).
The quality of the ultrapure water is monitored via a conductivity measuring
cell (LFP).
3.5.4 Final Purification Stage
The ultrapure water passes through a final filter as it is dispensed. A sterile
filter or an ultrafilter can be used as a final filter.
3.5.5 Circulation of the Ultrapure Water
To guarantee ultrapure water of consistent and high quality, the ultrapure
water purification system is constructed like a circulation ring:
— If no water is dispensed, the water circulates through the UV lamp
andthe ultrapure water cartridge.
— If there is no interaction with the device, the device automatically
switches to ECO mode.

Operating Design
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 15
4 Operating Design
4.1 Menu
All system settings and work steps for the maintenance of the device can be carried out in the menu.
Dispensing Care
Fill bag
6
5
4
3
1 2
Fig.7: Menu in Arium® Mini (Example)
Pos. Symbol Name Description
1Dispensing Opens the dispensing screen.
2Care Opens the “Care” menu.
3Fill bag Opens the wizard for bag filling (only with Arium®Mini).
4 Settings Opens the “Settings” menu.
5Information Opens the “Information” menu.
6Standby Switches to standby mode.

Operating Design
16 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
4.2 Dispensing Mode
In dispensing mode, the display shows information about the water quality and the fill level of the bag, as well as the
buttons relevant for dispensing.
0.055μS/cm c
20.3 °C
1
5 4 3 2
Fig.8: Dispensing mode Arium® Mini Plus (Example)
Pos. Symbol Name Description
1 Operating area Can display the following information:
— Current ultrapure water conductivity
— Current ultrapure water temperature
— Fill level of the bag (only forArium®Mini Plus andArium®Mini)
— Messages, warnings, errors
2Manual dispense Starts dispensing without preset dispense volumes.
3Volume input Opens a display for entering the dispense volume and starts the
dispensing.
4 Volume-controlled
dispensing
Starts dispensing with the most recently set dispensing volumes.
5Menu Opens the menu.

Operating Design
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 17
4.3 Message Display
The device displays three types of messages:
— Error messages (error):
— Dispense is not possible.
— The user only has limited options for troubleshooting errors.
— Warning messages (warning):
— Dispense is possible.
— The user can perform troubleshooting of warning messages.
— Status messages (info):
— Dispense is possible.
— There is information which the user should be aware of. Urgent action is not necessary.
Limits
11/14/2022 11:32
Ultrapure water quality
> 0.095 µS/cm c
1
2
3
Fig.9: Warning message (Example)
Pos. Symbol Name Description
1
Message symbol Indicates which type of message is present:
— Red symbol: Error message
— Yellow symbol: Warning message
— Gray symbol: Status message (info)
2 Message Provides information about the message:
— Error number or short description of a warning or status
message
— Date and time of the occurrence
— Message details
3Acknowledge Acknowledges the message.

Operating Design
18 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
4.4 Messages in Dispensing Mode
If several messages are active, the message list can be called up in the dispensing mode (see Chapter “4.5 Message
List,” page 19). The message list only appears when several messages are active and at least one message cannot
be displayed in the display for the conductivity or temperature of the water. If only one message is active, the message
is opened directly instead of the message list.
If an error message is active, no dispensing is possible. The three dispense buttons can be pressed, but when the user
tries to dispense, the error message appears again.
Messages
3
1
2
Fig.10: Message display in the dispensing mode (example)
Pos. Symbol Name Description
1Messages Message list Indicates that there is a message and opens the message list:
— Red symbol: Error message
— Yellow symbol: Warning message
— Gray symbol: Status message
2Value message Indicates that there is a message about a value and opens the
message list:
— Red symbol: Error message
— Yellow symbol: Warning message
3Bag fill level
message
Only forArium®Mini Plus and Arium®Mini:
— Indicates the fill level of the bag:
— Red symbol: The bag is empty. Water dispense is not possible.
— Yellow symbol: Only a little water can be dispensed.

Operating Design
Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential 19
4.5 Message List
All active messages can be viewed in the message list.
The messages in the message list are sorted according to priority. Error messages appear at the top. Within the same
priority level, the messages are sorted according to date and time.
Messages cannot be deleted manually. They remain in the message list and will be shown on the display until their
cause has been corrected. The device detects if the cause of a message has been corrected and automatically deletes
the message from the message list and the display.
Error
Error 0130
Care
Change nal lter
Care
Change cartridges
02/01/2021
11:46 AM
2/3/ 2021
9:33 AM
02/03/2021
2:17 PM
Messages
2
5
4
1
3
Fig.11: Message list (example)
Pos. Symbol Name Description
1Message symbol Indicates which type of message is present:
— Red symbol: Error Message
— Yellow symbol: Warning Message
— Gray symbol: Status message
2 Occurrence of the
message
Displays the date and time when the message occurred.
3 Message Displays and opens the message.
4 Brief description Displays the error number or a short description of the mes-
sage.
5 Message category Displays the message category:
— Error: Contact Sartorius Service.
— Care: Replace the consumable.
— Service: Contact Sartorius Service.

Operating Design
20 Operating Instructions Arium®Mini Plus|Arium®Mini|Arium® Mini Essential
4.6 Numeric Keypad
The numeric keypad is used to enter a dispensing volume orvarious system
settings.
Volume
1 2
3
4
5
6
START
Fig.12: Numeric keypad (example: Time input)
Pos. Symbol Name Description
1 Name of the
dialog box
Displays the name of the current
dialog box.
2 Numerical
value
Displays the currently entered
numeric value.
3START Confirmation Adopts the entered digit
sequence and returns to the
menu or to dispense mode.
4Correction Deletes the last digit entered.
5Delete Deletes all digits entered.
6 Numeric
Keypad
Transfers numerical values to the
dialog box.
Tip
When entering numeric values, it is only ever possible to select figures that
are permitted for the value.
Example: Entering a dispensing volume of more than 5liters is not possible.
The number fields 6 to 9 are therefore inactive for this entry.
t Pay attention to the validity of the numeric values.