Symmetry PR series User manual

PR Series
Precision Toploading Balances
USER MANUAL
(Software Revision: 2.35)
P.N. 8190, Revision A1, September 2006

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P.N. 8190, Revision A1, September 2006

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P.N. 8190, Revision A1, September 2006
CONTENTS
1.0 INTRODUCTION ..........................................................................................................4
2.0 TECHNICAL SPECIFICATIONS...................................................................................5
3.0 UNPACKING THE BALANCE.......................................................................................6
4.0 LOCATING THE BALANCE..........................................................................................6
5.0 SETTING UP THE BALANCE ......................................................................................7
5.1 ASSEMBLING THE BALANCE .............................................................................7
5.2 LEVELLING THE BALANCE.................................................................................7
5.3 WARM-UP TIME ...................................................................................................7
6.0 DISPLAY...................................................................................................................8
7.0 KEYPAD.......................................................................................................................9
7.1 NUMERIC ENTRY METHOD................................................................................9
8.0 INPUT/OUTPUT .........................................................................................................10
9.0 OPERATIONS............................................................................................................11
9.1 INITIALISATION..................................................................................................11
9.2 PASSCODES......................................................................................................11
9.3 WEIGHING..........................................................................................................12
9.3.1 Weighing Units.............................................................................................12
9.4 FUNCTIONS........................................................................................................13
9.4.1 Parts Counting..............................................................................................13
9.4.2 Percent Weighing.........................................................................................14
10.0 CALIBRATION..........................................................................................................15
11.0 RS-232 INTERFACE ................................................................................................16
12.0 ERROR CHECKING.................................................................................................19
13.0 SUPERVISOR MENUS ............................................................................................20
13.1 ENABLE WEIGHING UNITS...............................................................................20
13.2 ENABLE WEIGHING MODES.............................................................................21
13.3 ENABLE SERIAL INTERFACE PARAMETERS..................................................21
13.4 SETUP PARAMETERS.......................................................................................23
13.5 CALIBRATION SETUP........................................................................................24
13.6 PASSCODES......................................................................................................25
13.6.1 Forgotten Passcodes ...................................................................................25
14.0 SAFETY AND MAINTENANCE ................................................................................26
15.0 TROUBLE-SHOOTING.............................................................................................26

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P.N. 8190, Revision A1, September 2006
1.0 INTRODUCTION
Thank you for selecting the Precision Balance.
This Instruction Manual will familiarise you with the installation, trouble-
shooting, general maintenance of the balance, etc. and will guide you through
the various applications.
Please read this Manual thoroughly before starting the operation. If you need
any clarifications, feel free to contact your supplier.
PRODUCT OVERVIEW
This Precision Balance is ideal for laboratory and general purpose weighing.
FEATURES:
•Large easy to read LCD display with backlight
•Applications include weighing, parts counting and percentage
weighing
•External calibration
•Bi-directional RS-232 interface
•Can be configured to print a GLP Compliant report after each
calibration to include the time, date, balance number and a
verification of the calibration
•Automatic temperature compensation
•Display in 4 languages- English, French, German and Spanish
•Multiple weighing units
•Date and time
•Easy to use, sealed keypad
•Below balance weighing facility
•Password protection
•Security locking point
•Robust metal casing

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P.N. 8190, Revision A1, September 2006
2.0 TECHNICAL SPECIFICATIONS
210g model 410g model 2200g model 4200g model
Maximum
capacity 210g 410g 2200g 4200g
Readability 0.001g 0.01g
Typical
Repeatability 0.002g 0.02g
Linearity (±) 0.003g 0.03g
Tare range Full
Units of
measure grams, milligrams, kilograms, carats, pennyweights, grains, troy ounce, ounces
Interface RS-232 bi-directional
Operating
temperature 10°C - 40°C
Power supply 15 VDC, 50/60 Hz, 800 mA
Calibration External
(Selectable automatic calibration due to change in time or temperature)
Display Backlit LCD with dual digits (24 mm high)
Draught
shield Supplied as standard for 0.001g units
Housing Die cast aluminium housing
With glass draught shield (for 0.001 g units)
Pan size 140 mm x 140 mm /
5.5” x 5.5” 200 mm x 175 mm / 7.9” x 6.9”
Overall
dimensions
(w x d x h)
251 × 358 × 104 mm /
10” x 14.3” x 4.2”
Net weight 5.5 kg / 12 lb
Applications Weighing, Parts counting, Percentage weighing

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3.0 UNPACKING THE BALANCE
Remove the balance from the packing by carefully lifting it out of the box.
Inside the box you will find everything needed to start using the balance-
AC adapter
Four plastic pan supports
Stainless Steel Top Pan
Breeze / draught shield (For 0.001g models)
This User Manual
4.0 LOCATING THE BALANCE
•The balance should not be placed in a
location that will reduce the accuracy.
•Avoid extremes of temperature. Do not place
in direct sunlight or near air conditioning
vents.
•Avoid unsuitable tables. The table or floor
must be rigid and not vibrate.
•Avoid unstable power sources. Do not use
near large users of electricity such as welding
equipment or large motors.
•Do not place near vibrating machinery.
•Avoid high humidity that might cause
condensation. Avoid direct contact with water.
Do not spray or immerse the balances in
water.
•Avoid air movement such as from fans or
opening doors. Do not place near open
windows or air-conditioning vents.
•Keep the balance clean. Do not stack material
on the balances when they are not in use.
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5.0 SETTING UP THE BALANCE
5.1 ASSEMBLING THE BALANCE
•Locate the balance on a solid surface, free from vibration
•Gently place the 4 pan supports (if not already fitted) and then the
stainless steel pan on the weighing platform
•Place the windshield frame and the top cover around the pan (for
0.001g models)
•Level the balance using the adjustable feet and spirit level
•Connect power to the balance
•For best performance, let the balance warm up for 30-60 minutes and
calibrate before using
5.2 LEVELLING THE BALANCE
After placing the balance in a suitable place,
level it by using the spirit level on the rear of the
balance. To level the balance turn the two
adjustable feet at the rear of the balance until
the bubble in the spirit level is centred.
5.3 WARM-UP TIME
Attach the power supply cable to the connector
on the rear of the balance. Plug the power
supply module into the mains. The display will
indicate the balance serial number (if set) and
the software revision number followed by the
capacity of the balance. Next the balance will
run a self-test by displaying all segments and
then will show zeroes accompanied by the zero
symbol. If the balance serial number is not set,
the display will show dashes.
Before you start weighing, you have to wait for the balance to achieve a
stable internal temperature. Typical initial warm-up time suggested for a
balance already at room temperature is about 1 hour.
A stable sign ~ is shown when the balance is in
stable condition. It will turn off if the balance is
not stable. Exact zero is shown when the “0“
symbol is on to the left of the display area.
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6.0 DISPLAY
This display includes areas for the weight value (up to 7
digits), symbols for common weighing units, tare, stability, zero
and low battery and a text area for menu.
The LCD has 7 x 7-segment digits for the weight and 10 x 14 -
segment digits for messages, symbols for weighing units and
indicators such as stability etc.
The 14 segment digits area is used to display messages
concerning operation or errors.
The 10 digit text area is used to display the current weighing
mode or to guide the user through the operation.
SYMBOLS AND INDICATORS
The LCD has unique symbols to indicate the following:
0Zero
Stable
g, oz, ozt, GN, dwt,
ct, Kg, mg, Pcs, % Text is shown for the weighing units and modes
“CAL” When calibration is occurring or about to occur
“ºC” When a temperature is shown or a calibration
is requested due to change in temperature
“ti” For a time driven calibration
“Net” When a net weight is shown
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7.0 KEYPAD
The keypad has the following keys to operate the balance.
Keys Primary function Secondary function
[On/Off] To turn the balance to ON or
OFF -
[Tare] or [Esc] A combined zero and tare
function To escape from setup functions and modes
[Cal] / or 
[Up]
Starts the calibration function
To increment or change a
displayed value or scroll
through options forward
[Print] / or
[Back] Instructs the balance to print data To advance a flashing digit by one position to the left
[Setup]/
or [Enter] Enters a function To save a value during setting up a function such
as entering unit weight
[Mode] / or
[Advance] Selects functions by cycling through a set of enabled
functions, for example parts
counting or percent weighing
To advance a flashing digit
by one position to the right
To go back by one step
during setup functions
[Units] / or
[Down] Selects weighing units by cycling through a set of
enabled units
To decrement or change a
displayed value or scroll
through options backwards
[Mode] / or
[Advance] Selects functions by cycling through a set of enabled
functions, for example parts
counting and percent weighing
To advance a flashing digit
by one position to the right
To go back by one step
during setup functions
7.1 NUMERIC ENTRY METHOD
To set a value when required, use the keys as given below-
- [Up] and [Down] keys to increase or decrease the flashing digit,
- [Advance] and [Back] keys to advance or move back the digit and
- [Enter] key to accept the value
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8.0 INPUT/OUTPUT
The rear panel has connectors for RS-232 serial and
buffered I2C-bus interfaces and a power input socket.
Required power input is a low-voltage external supply,
15VDC @ 800mA.
Various communication options, e.g. USB, LAN, Wireless,
will be implemented in the future via add-on “black-boxes”
which will convert the RS-232 serial output or I2C to the
desired protocol. The basic unit includes RS-232 serial
communications only.
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9.0 OPERATIONS
9.1 INITIALISATION
When the balance is first switched on, it
will display the balance serial number (if
set), software revision, model capacity
and then all segments on the display will
be shown. Overall the time taken is
usually 5 -10 seconds.
If a passcode has been set, the display will show “PASSCODE” and the main
display will show a zero. In this case you must enter the passcode to
continue using the numeric entry method (see section 7.1). A different
passcode may be set for a Supervisor to weigh or to have access to the
selected User menus. If the passcode has not been set the balance will
continue as below.
The display will show zero reading along
with the zero symbol “0”and the
weighing unit last used. If automatic
time calibration is enabled the balance
will calibrate after power up and again
after the pre-set time interval.
9.2 PASSCODES
If a passcode has been set to limit access to the weighing functions of the
balance the display will show “PASSCODES” with the main digit set to zero.
The display will change to show 7 digits set to zero with the rightmost digit
flashing. Use the numeric entry method (see section 7.1) to enter the code. It
will be necessary to enter the correct passcode to continue. See the Section
13.6 for details.
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P.N. 8190, Revision A1, September 2006
9.3 WEIGHING
•Press [Tare] to zero the balance, if required
•“0“ will be displayed
•Place a mass on the pan and the weight will be displayed
•If a container is used press [Tare] to tare the balance when the stable
symbol “~” is on. “Net” will be displayed to indicate that the balance is
tared
•When the display shows zero, place the item to be weighed. Only the
net weight will be displayed
•At any time the [Units] key can be pressed to select another unit. Use
the [Up] or [Down] key to scroll through the units and select the desired
unit by pressing [Enter], the display will change to show the weight in
the selected weighing unit. The available weighing units can be enabled
or disabled by the user (see section 13.1). Only weighing units that
have been enabled will be cycled through when [Units] is pressed
9.3.1 Weighing Units
You can select alternative weighing units to display the weight by pressing
the [Units] key. The common weighing units are:
Unit Symbol Models Conversion Factor
1g = Conversion Factor 1 unit = grams
1. Grams g All 1 1.0
2. Milligrams mg not 0.01g units 1000 0.001
3. Kilograms kg All 0.001 1000
4. Carats ct All 5 0.2000
5. Pennyweights dwt All 0.643014865 1.555174
6. Grains GN All 15.43236 0.0647989
7. Troy ounces ozt All 0.032150747 31.103476
8. Ounces oz All 0.035273962 28.349523
It is possible to set the balance to display only grams. Grams will always be
one of the units enabled, by default.

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P.N. 8190, Revision A1, September 2006
9.4 FUNCTIONS
When weighing, the user can access the applications that have been enabled
(see section 13.2).
The following applications are available in this version (2.35):
•Parts counting
•Percent weighing
The functions can be enabled or disabled using a similar method to the Units
above by turning the functions to on or off.
9.4.1 Parts Counting
A known quantity of sample is first weighed to compute an average unit
weight and then an unknown quantity of the sample is weighed. The net
weight of this unknown sample is divided by the average unit weight to
display the quantity. The result is always a whole number.
The balance will have a preset number of parts to be used as a sample.
These values are 10, 25, 50 or 100 items.
•Press [Mode] to show parts counting, “PARTS” will be displayed
•Enter parts counting by pressing [Enter]
•Press the [Up] or [Down] key to select the sample size, “REF QTY”,
10, 25, 50, 100, etc., then press [Enter] to confirm
•When “LOAD XX Pcs” is shown place XX number of items on the pan
and press [Enter] to compute the average piece weight
•Remove the sample when display shows “XX Pcs” and then place an
unknown quantity on the pan. The balance will then compute the
number of parts based upon the average piece weight. The display will
show the result in Pcs
•To count another item press [Mode] and continue as before
•Checks will be made to determine that the weight of the reference parts
is large enough for reasonably accurate counting (weight of each piece
should be > 1d)
•To return to normal weighing, press [Mode] to show “REF QTY” then
press [Esc]

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P.N. 8190, Revision A1, September 2006
9.4.2 Percent Weighing
Percent weighing is carried out by defining a sample weight as 100%. The
sample weight can either be entered by the user or taken from a sample
•Press [Mode] and then the [Up] or [Down] key to select Percent
weighing, “PERCENT” will be displayed
•Press [Enter] to enter the function
•Display will show, “PERCENT SAMPLE”
•Press [Enter] to select the sample method
•When “LOAD 100 %“ is shown, add the sample
•Press [Enter] to set this weight to be 100%. When ready the display will
show “100%”
•Remove the sample and place an unknown sample to display the
percentage weight
•To set another weight as 100%, press [Mode] and continue as before
•To manually enter a value to be set as 100%, press [Up] or [Down] key
when “PERCENT SAMPLE” is shown to select “PERCENT Ent Wt”
•Press [Enter] to select the manually entered weight method
•Enter the weight using the numeric entry method (see section 7.1)
•Place unknown sample to display the percentage weight
•To perform percent weighing with another sample press [Mode] and
continue as before
•To return to normal weighing, press [Esc]
Note: Percentage will be displayed to the maximum number of decimal
places based on the resolution of the balance. To increase or decrease by
one decimal place, press the [Up] or [Down] key respectively.

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P.N. 8190, Revision A1, September 2006
10.0 CALIBRATION
The balances are calibrated using an external mass.
•Press the [Cal] key to start calibration.
•Pressing [Esc] will abort the calibration at any time
•Check the display is at zero. Tare, if necessary
•Press the [Cal] key
•Display will show “LOAD 0”. Ensure the pan is empty and press [Enter]
•The balance will then show the value of the calibration mass required,
for example “LOAD 2000 g”
•Place the suggested mass on the balance. Press [Enter] to continue
•When the calibration is complete, balance will return to normal weighing
The balance will have the ability to ask for calibration when the following
conditions occur. This feature can be enabled or disabled by the user (see
section 13.5). The conditions are:
1. Internal temperature change greater than a preset amount, typically 2ºC
2. Time since last calibration exceeds a preset time, typically 4 hours or 15
minutes after power is applied
The user will know a calibration is asked for from flashing of the “CAL” symbol
on the display. The display will show a 5 second countdown when calibration
will start. If the user presses the [Esc] key the calibration will be delayed by
one minute to allow for a process in progress to be finished. As soon as the
balance is calibrated the symbol will be turned off.
Suggested calibration weights
210g model 200g
410g model 200g
2200g model 2000g
4200g model 2000g
Calibration Errors
Occasionally during calibration an error will be detected. These errors can be
caused by unstable readings, improper weights being used, large shifts of
zero from the factory settings, etc. When an error is found a message will be
shown and the calibration must be done again.

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P.N. 8190, Revision A1, September 2006
11.0 RS-232 INTERFACE
The balances have the ability to send data to the serial interface.
The weighing data can be sent over the interface either automatically or when
the user presses the [Print] key.
The user has control over what data is to be printed.
The following gives a description of the RS-232 interface.
HARDWARE
The RS-232 interface is a simple 3 wire connection. The input and output
connections are:
Connector: 9 pin D-sub miniature socket
Pin 2 input to balance RXD
Pin 3 output from balance TXD
Pin 5 Signal ground GND
Handshaking is not applied.
Baud rate: 4800, 9600, 19200, 38400
Parity: NONE (=8N1), EVEN (=7E1) or ODD (=7 O 1)
All lines are terminated with carriage return and line feed (<CR><LF>).
In continuous output mode, or if single-line output on demand is selected, the
serial output format will be a single line in the form “1234.567 g<CR><LF>”.
The format of the single-line output will change depending on the mode in
which the balance is operating, as described below.
If output on demand is selected, the user may optionally configure the serial
output as a choice of 3 styles of form, either in a default format or in one of
two custom formats. Each of the custom formats can be configured to output
up to 15 lines of data. The data types that can be printed are:
NAME TEXT PRINTED
ID number ID no.: xxxxxxxxxxxx
Serial number Serial no. xxxxxxxxxxxx
Date DATE dd/mm/yyyy
Time TIME hh:mm:ss
Net weight Net: xxx.xxx g
Gross weight Gross: xxx.xxx g

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Tare weight Tare: xxx.xxx g
Unit weight Unit wt: xxx.xxx g
Count Count: xxxx pcs
Reference weight Ref. wt: xxx.xxx g
Percent Percent: xx.xxx %
A blank line printed <CR><LF> only.
Any of these can be printed on any of the 15 lines available. Not all items
need to be used and any one can be used more than once (see section 13.3).
The data for each form will be preceded by a start-of-header <SOH>
character (01) and terminated with an end-of-transmission <EOT> character
(04). These characters will be ignored by a serial printer but will allow a
computer program which reads the data to distinguish between this block
report format and the single-line output format described above.
STANDARD FORMAT
The balance will print the following data as the standard form. The standard
form cannot be changed. The format of the custom forms #1 and #2 will be
the same as the standard form until modified by the user.
Line 1 Date
Line 2 Time
Line 3 Blank line
Line 4 ID number
Line 5 Blank line
Line 6 Result
Line 7 Blank line
Line 8 Blank line
This will result in a printout that looks like:
Date: 23/09/04
Time: 15:45
ID No: 123456
Net: 123.456 g
*NOTE: The format of the results line will change depending on the mode in
which the balance is operating, e.g.
Normal weighing: “123.456 g”
Parts Counting: “1234 pcs”
Percent weighing: “12.345 %”
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P.N. 8190, Revision A1, September 2006
INPUT COMMANDS USING REMOTE KEYS
The balance can be controlled with the following commands sent using
remote keys such as from a PC. The commands must be sent in upper case
letters, i.e. “KT” not “kt”. Press the Enter key of the PC after each command
(the action of Carriage Return is denoted as <CR> as shown below).
Basic Input Commands:
!KT<CR>
Tares the balance to display the net weight. This is the same as pressing
the [Zero / Tare] key when the balance is in the normal weighing mode.
!KS<CR> Enters the Setup section. This is the same as pressing the [Setup] key
when the balance is in the normal weighing mode.
Once entered the Setup section, the balance can be controlled remotely
using the Input Commands (as mentioned in this table) which will perform
the same key functions as described in section 13.0.
!KP<CR>
Transmits data over RS-232 interface. This is the same as pressing the
[Print] key when the balance is in the normal weighing mode.
!KM<CR> Enters the Modes section. This is the same as pressing the [Mode] key
when the balance is in the normal weighing mode.
!KC<CR> Enters the Calibration section. This is the same as pressing the [Cal] key
when the balance is in the normal weighing mode.
!KU<CR> Enters the Unit selection section. This is the same as pressing the [Units]
key when the balance is in the normal weighing mode.
Invalid Input Command:
If an invalid command is received, then the command is returned as follows-
Invalid Command Message returned Remarks
!NT<CR> !EU<CR> Command character is not ‘K’
!KK<CR> !EK<CR> Key character is not ‘T’, ‘S’, ‘P’, ‘M’, ‘C’
or ‘U’
!KT-<CR> !EF<CR> Command format error, <CR> is not
the fourth character
KT<CR> or
!KT - No reply Either ‘!’ or <CR> is missing in the command string

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P.N. 8190, Revision A1, September 2006
12.0 ERROR CHECKING
During weighing the balance is constantly checking to see if the balance is
operating within the limited parameters. The errors likely to occur are:
A/D counts below lowest allowed value
A/D counts above highest allowed value
A/D not operating
Maximum capacity exceeded
Other errors may be detected during special functions or operations. These
will be described in the section that applies.
Error messages and the reasons are:
Concerning A/D counts
ERROR ADc UL A/D counts below a limit
ERROR ADc OL A/D counts above a preset limit
Concerning calibration
ERROR St Calibration could not be completed because the results were not stable
ERROR LO or ERROR HI Calibration constant not within 20% of old
calibration constant
Concerning weighing
ERROR LO Weight display is below zero by >4%max
ERROR HI Weight is above maximum plus 90d

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P.N. 8190, Revision A1, September 2006
13.0 SUPERVISOR MENUS
Pressing the [Setup] key while in normal weighing gives access to the
Supervisor menus.
•When [Setup] is pressed and passcodes are not enabled, the display
will show the message “SUPERVISOR”. If passcodes are enabled, the
balance will ask for it by displaying “PASSCODE 0”
•If a wrong code is entered an “ERROR CODE” message will flash and
the balance will return to weighing mode
•If the passcode has been enabled and entered, the balance will allow
the operator to access the Supervisor’s menus
•When the display shows “SUPERVISOR”, press [Enter] to view the
parameters that can be modified
•From this menu the user can enable/disable weighing units or modes,
set balance parameters for the conditions, set time and date, set
parameters for the RS-232 interface, calibration parameters and
security parameters
•The [Up] and [Down] keys will cycle through the main parameters,
pressing the [Enter] key will enter the parameters and sub-parameters
or options can be set. Press [Mode] to come out of a sub-parameter
or press [Esc] to return to normal weighing from any parameter
13.1 ENABLE WEIGHING UNITS
•When “UNITS” is displayed, press [Enter]. The display will show the
symbol for the first unit, e.g. carats, ct, together with its enable state
“OFF” or “On”. The user can then enable or disable the carats unit by
using [Up] or [Down]. Pressing [Enter] will confirm the setting and will
advance to the next weighing unit. Repeat for each weighing unit in
turn. Gram is always set to “On”
•Press [Mode] to advance to setting of the next menu or press [Esc] to
return to normal weighing