Optima Scale OPD-E User manual

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OPD-E Analytical Balance
Maintenance Manual
Menu
Chapter I: Count Value Adjustment
Chapter II: Balance Adjustment
Chapter III: Corner Error Adjustment
Chapter IV: Model Setting
Chapter V: Linearity Calibration
Chapter VI: External Weight Calibration
Chapter VII: Correction of Internal Calibration Weight Value
Chapter VIII: 200g Full Scale Correction
Chapter IX: Temperature Compensation
Chapter X: Inspection
Chapter XI: Failure and Maintenance

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Chapter I: Count Value Adjustment
I. Disassembly of Balance Shell:
1. Disassembly of rear cover: Remove three M4 inner hexagon screws under the rear label of the
balance and then disassemble the rear cover.
2. Disassembly of lower cover plate: erect the balance, remove 6 pieces of M3 cross-head screws
and then disassemble the stainless steel rear cover of the balance.
3. Disassembly of upper cover plate: remove two front M4 inner hexagon screws under the
balance and then disassemble the upper cover plate.
4. Disassembly of baffle: remove two middle M4 screws under the balance and then loosen the
baffle.
5. Disassembly of windshield: remove two M3 inner hexagon screws at the front in the balance
and then loosen the front glass of the windshield. After that, press the left and right glass (note:
adhesive strips for the left and right glass are pasted in the sheath) and then remove the entire
windshield.
II. Adjust the Zero and Full Scale Count Value:
1. Adjust the balance, install the balance pan and the balance pan bracket, and then switch on the
power supply.
2. Under the standby condition, only the decimal point flickers or “PEFIL” is displayed or only
the ON sign is displayed on the LCD.
3. Press CAL and then 1 is displayed on the LCD; press TARE and then 2 is displayed on the
LCD; after that, press CAL again, 3 is displayed….
4. Press CAL and TARE alternately until 8 is displayed on the LCD.
5. Press ON/OFF, and then the balance displays 8888888.
6. Press TARE to display the balance type. Then press TARE again to display set values of
internal parameters.
7. Press CAL to display the zero point count value.
8. By increasing or decreasing the balance weight, the zero point count value of the balance is

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close to 400 as much as possible and the zero point count value is between 350 and 450: (increase
or decrease the weight on 8 fixed screws of the bracket or M4 screw holes in front of the column,
so as to achieve the standard between 350 and 450).
9. Full load count value: load a 200g standard weight on the balance pan to observe the full scale
count value. The full load count value is between 15200 and 15550.
10. If the full load count value is excluded in the above scope, an electric resistance box shall be
connected at R25 so as to ensure the full load count value in the said scope through the parallel
connection of relevant resistance.
III. Check Counter Value:
The no-load counter value scope is from 350 to 450. After the 200k weight is loaded, the full load
count value shall be between 15200 and 15550.
IV. Assembly:
Components of the balance shall be assembled well according to the sequence opposite the
disassembly sequence after checking.
Chapter II: Balance Adjustment (4MM adjustment)
When the balance is under the condition A and B, observe the change of the balance value.
(Condition A means the balance is at the horizontal position, condition B means that a gasket
4mm thick is placed at the front bottom of the balance to increase the front height of the balance
by 4mm), and then compare readings of the balance under the two conditions.
1. Roughly adjust the balance weight and keep the difference of values displayed under both
condition A and B in the scope of ±80. If the value under the condition A is higher than the value
under the condition B, the balance weight shall be decreased. On the country, the weight shall be
increased.
2. During the adjustment, pay attention to adjusting properly and do not damage the force spring
and pivot spring. When you tighten screws of the balance weight, hold the beam by hands and
avoid moving the beam.
3. Adjust the balance weight slightly and keep the difference of values displayed under both
condition A and B in the scope of ±30.
4. Check the count value again and make a fine adjustment after the balance adjustment is
finished.

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Beam
Balance weight assembly
Gravity weight assembly
Stopper
Cross recess head screw M3x6
Flat washer 3
Chapter III: Position Error Adjustment
1. Use a 100g weight to adjust the position error after the balance is preheated for 40min. Check
the value displayed at five positions of the balance, i.e. up, down, left, right and middle. Then,
make a contrast with the value displayed in the middle. When the error is more than 0.2mg, make
an adjustment with the following method:
2. On the basis of displayed position data and differences with data at the middle position, adjust
position adjustment screws in the direction indicated by arrows in the picture above, until they
meet the scope requirement.
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Chapter IV: Model Setting Procedures
1. Under the standby condition, only the decimal point flickers or “PEFIL” is displayed or only
the ON sign is displayed on the LCD.
2. Press CAL and then 1 is displayed on the LCD; press TARE and then 2 is displayed on the
LCD; after that, press CAL again, 3 is displayed….
3. Press CAL and TARE repeatedly until 9 is displayed on the LCD.
4. Switch ON/OFF, and then the balance displays 8888888.
a) Press TARE to display the relevant balance type.
b) Press CAL repeatedly to choose the balance type you need. When the balance type you need
is displayed, press TARE. Then, setting is finished. The balance displays “-1 112111”.
c) Swith-ON
Remark:
There are 10 internal models for this type of balance: 200, 180, 120, 60, H200, H180, H120, H60,
600c and 150c.
Chapter V: Linearity Calibration
1. Switch on power and preheat it for 30min. and adjust the gradienter to the horizontal position.
2. Press ON/OFF and then the balance displays the switch-off sign.
3. Press CAL and then 1 is displayed on the LCD; press TARE and then 2 is displayed on the
LCD.
4. Press CAL and TARE repeatedly until 8 is displayed on the LCD.
5. Switch ON/OFF, and then the balance displays 8888888.
1) Press CAL to enter Lnr;
2) 3s later, the balance will display Lnr in. 3s later, Lin… is displayed and the balance
carries out the zero point calibration. About 3s later, the balance displays Lin50 and

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prompts to load a 50g standard weight on the scale pan. After that, press TARE and the
balance displays Lin. and then Lin 100. Load a 100g standard weight, press TARE, and
the balance displays Lin… and then Lin 150. Load a 150g weight, press TARE, and then
the balance displays Lin… Several seconds later, the balance calibration is finished and
the balance displays 0.0000g.
3) Take away the weight on the scale pan and press TARE for zeroing, and then the
calibration is over.
4) Remark: Correct external weights once or for many times after the calibration is
finished, until the reading on the balance is the same with the weight value. Refer to
“Balance Calibration” for the specific calibration method.
Chapter VI: External Weight Calibration
The balance calibration can be classified into external weight calibration and internal weight
calibration. Before the calibration, switch on the power and preheat for 30min and adjust the
gradienter to the horizontal position.
1. External weight calibration (for external calibration balance): for external calibration
balance, it is confirmed that the internal parameter is C1-1.
A. Press CAL and the balance displays “CAL IN” and then “CAL…” and calibrates the zero
point.
B. 3s later, the balance displays “Cal dn” and prompts to load the 100g standard weight to the
center of the scale pan.
C. The balance displays “CAL…” and calibrates the position of the 100g standard weight.
D. After the calibration, the balance displays “Cal up” and prompts to take away the weight on
the scale pan.
E. After the weight is taken away, the balance displays “CAL…” and then “Cal end”. Then, the
external weight calibration is over.
F. 2s later, the balance returns to the zero position automatically. When “0.0000” is displayed, the
calibration is over.
G. After the balance calibration is finished, use the full scale weight (e.g. 100g or 200g standard
weight) for testing, be sure that the indication on the balance is in consistent with the weight
value and the error shall have no more than 3 bits. If the error has more than 3 bits, the balance
shall be calibrated again.

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2. Internal weight calibration: for internal calibration balance only: the parameter shall be
set as C1-0 before calibration.
A. Press CAL and then the balance displays “Cal in”. 2s later, the balance displays “Cal…” and
calibrates the zero point.
B. After that, the balance displays “Cal in” and the motor loads the internal weight to the internal
weighing bracket automatically. When the motor stops rotation, the balance displays “Cal…” and
calibrates the internal weight automatically.
C. After the calibration is over, the balance displays “Cal up”, the motor moves away the weight
automatically and the balance displays “Cal…”.
D. 2s later, the calibration is over, the balance returns to the position of zero point, and 0.0000g is
displayed.
In the same way, after the balance calibration is over, use a full scale weight (e.g. 100g or 200g
standard weight) for testing, be sure the indication on the balance is in consistent with the weight
value and the error shall have no more than 3 bits. If the error has more than 3 bits, the balance
shall be calibrated again.
Chapter VII: Correction of Internal Calibration Weight Value
Background reference: for an internal calibration balance, its built-in weight grade shall be lower
than E2 or F1 and the error shall be higher than the permissible tolerance of the balance. In order
to eliminate the D-value between internal and external weights, the parameter correction is
specially set.
Note: This setting is limited to internal calibration balances only. When the internal weight
calibration is used for internal calibration balance and the D-value is more than 1 in comparison
with external standard weight, the internal weight value shall be adjusted.
1. Under the standby condition, only the decimal point flickers or “PEFIL” is displayed.
2. When “PFAIL” is displayed, press ON/OFF to keep the decimal point on.
3. Press CAL and the LCD displays 1; press TARE again and the LCD displays 2 again.
4. Repeatedly press CAL and TARE until the LCD displays 7.
5. Press ON/OFF and the balance displays the weight value L100.0012.
1) Press CAL and the value 100.0000 flickers;

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2) Press CAL and reduce the weight value. (After the internal weight calibration, use the
external standard weight for checking and the indication value shall be higher than the standard
value of the external weight).
3) Press SET and increase the weight value. (After the internal weight calibration, use the
external standard weight for checking and the indication value shall be lower than the standard
value of the external weight.)
4) Press TARE, save the weight value and exit.
5) Press ON/OFF to return to the standby condition.
6) After setting, check the setting result. Firstly, calibrate the internal weight and use the
external weight to verify the correctness.
Note: When linear calibration is carried out for the weight, be sure to return the set value of the
internal weight to the system default 100.0000.
Chapter VIII: 200g Full Scale Correction
Note: After the linear calibration for the balance, check the value at each testing point. If the
value is between 180g and 200g, the linear performance is poor and the value at the 200g point
can be corrected. The corrected value equals to the D-value with the standard value after the 200g
standard weight is loaded.
1. Switch on the balance.
2. When the balance is on normally and displays zero point, press SET to enter the set menu.
3. Press MODE to set the D-value parameter as “200.0000”.
4. Press TARE for correction and then “Add XXX” is displayed.
5. Press MODE to modify sign bits.
6. Press PRINT to modify data bits, ±29 at most.
7. Press TARE to confirm to save.
8. Press ON/OFF to exit.
9. After correction, check the linear error at each point again and the error value shall be no more
than 2D.

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If a 200g weight ordinarily weights 200.0028g, set “add -28” and then save it only.
If a 200g weight ordinarily weights 199.9991g, set “add +09” and then save it only.
Chapter IX: Temperature Compensation Method under high or low temperature
1. Switch on the balance, preheat it for half an hour and adjust it horizontally. Calibrate and test it
at the room temperature. If the balance is qualified, switch it on in the lab at high and low
temperature and also adjust it horizontally.
2. Enter the high and low temperature status: Press ON/OFF and then the balance displays “ .
“. Press CAL and TARE and then the balance displays 8. Press ON/OFF and then 888888 is
displayed. After TARE is pressed twice and then CAL is pressed, the balance displays the count
value. After you press CAL again, the balance displays zero point value (temperature
compensation value).
3. Procedures for setting the temperature of the low and high temperature lab: humidity: 60%,
temperature: 10 (2h) ------35 (3h) ----------10 (3h). It takes 6h for every circulation to make
the balance display the count value.
4. When the temperature rises, the display value goes up (i.e.: high temperature value – low
temperature value = 0) and the polarity is anode.
5. Zero point adjustment: tt=zero point high temperature count value – zero point low
temperature count value
VRtt correction=tt*10/ temperature difference
Vt adjustment=VRtt correction /6 (i.e. the number of adjusted
potentiometer rings)
Full scale adjustment: st=(high temperature full scale count value – low temperature full
scale count value) -tt
VRst correction=st*7/ temperature difference
Vs adjustment=VRst correction/6 (i.e. the number of adjusted
potentiometer rings)
VR adjustment direction:
Zero point adjustment:
When R5 (R4, J4) is adjusted, rotate R5 to the right end and then rotate it leftward for 15
rings. Short-connect the needle 1 and 2 as well as 4 and 5 of J4. Then, make an adjustment
according to the polarity. 1. If the polarity is negative, adjust R5 leftward (in the anticlockwise
direction); if the polarity is positive, adjust R5 rightward. If the polarity is still negative when R5
is rotated to the leftward end, short-connect 2 and 3 as well as 5 and 6 respectively. Make an

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adjustment again: readjust it in the previously opposite direction. If the polarity is negative, adjust
R5 to rightward (in the clockwise direction). If the polarity is positive, adjust it leftward. The
number of adjusted rings shall be adjusted according to Vt. 2. On condition that needle 1 and 2, 4
and 5 of J4 are short-connected respectively, if the polarity is still positive when R5 rotates to the
rightward end, the resistance of R4 shall be increased.
Full scale adjustment:
Adjust R14. At the beginning, rotate it to the rightward end and then leftward for 15 circles.
Then, make an adjustment according to the polarity. Adjust it rightward if the polarity is positive.
When it is impossible to adjust rightward anymore, reduce the resistance of R13. Adjust it
leftward if the polarity is negative. When it is impossible to adjust leftward anymore, increase the
resistance of R13.
Chapter X: Inspection
I. Corner Error Test:
Switch on the balance, preheat it for half an hour and adjust it horizontally. Use a 100g standard
weight to perform the position error test for the balance. (Set the zero point track of the balance
as C3-0 before the test. Refer to the manual for details about the setting method.
1. Tare the balance.
2. Put the 100g standard weight in the middle of the balance and record the reading of the
balance.
3. Then, put the weight at the up, down, left and right positions gradually, check the reading of
the balance and make a record.
4. It is required that the position error of the balance shall be within ± 2D. If the error exceeds the
scope, the four positions shall be adjusted.
II. Repeatability Test:
1. Tare the balance.
2. Put the half-scale and full-scale standard weight in the middle of the balance, perform the test
for 6 times continuously and record the reading of the balance.
3. The repeated error of the balance shall be within ±3D.