STANDARD OPERATING PROCEDURE AA SERIES AA-160 PRECISION BALANCE

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1 Table of Contents Page 1. Scope 2 2. Objective 2 3. Definitions 2 4. Responsibility 3 5. Procedure 3 6. Precautions References Appendices Revision History 12 Original Authorised Copy for: Reading Copy Written by: Reviewed by: Approved by: Signature/Date: Signature/Date: Signature/Date: Page 1 of 14

2 1. Scope This Standard Operating Procedure (SOP) applies to the staff and students using the AA Series AA-160 Precision Balance in the laboratories of the Pharmacy Department, University of Malta. 2. Objective To describe the procedure for the installation, configuration, operation, calibration, maintenance and troubleshooting of the AA Series AA-160 Precision Balance. 3. Definitions 3.1. Adjustable Feet: Circular screws situated at the bottom of the balance that are manipulated to level the balance out Auto CAL Key: To initiate automatic calibration using internal weights Calibration: A procedure to check a measuring instrument against an accurate standard to determine any deviations and correct for errors Calibration Variance: The corrections made to the calibration values to compensate for differences between the actual weight being used and the desired value Configuration Parameters Set-Up Menu: Allows the user to adapt the balance to different weighing situations (see /A1) Message Display: Part of the dual LCD display that uses text to provide additional information Number Display: Part of the dual LCD display that continuously shows the weighing results On/Off Key: To turn the display ON or OFF or to enter the desired option in the Set-Up menu Print Key: To transmit sample weight to printer or computer. Is also used to scroll through the different options in the Set-Up Print menu. Page 2 of 14

3 3.10. Select Key: To scroll through the configuration parameters of a particular option in the Configuration Parameters Set-Up menu Set-Up Key: To access the Configuration Parameters Set-Up menu and then to cycle through its options. Is also used to access the Set-Up Print menu Tare: Allows the balance to display the weight of the sample only and not the combined weight of the sample and its container Tare Key: To set the Numeric Display to zero. Is also used to exit Set- Up menu and return the balance to normal weighing mode U symbol: An unstable indicator that is automatically displayed whenever the balance is not stable and then disappears when the balance becomes stable Weighing Pan: The area on top of which the material to be weighed is placed. 4. Responsibility 4.1. The members of the Department of Pharmacy (staff and students) are responsible for following this SOP The designated Laboratory Officer or Laboratory Assistant is responsible for ensuring that this SOP is followed. 5. Procedure 5.1. Installation Place the balance on a stable surface, away from any vibrations Turn the adjustable feet at the bottom of the balance clockwise or anticlockwise until the air bubble in the spirit level is in the centre of the marked circle Insert power supply connector in the plug on the rear of the balance and plug the power supply into the mains supply Press the On/Off key to switch on the balance Wait until the start-up message and then are displayed before starting to operate the balance. Page 3 of 14

4 5.2. Configuration Press the Set-Up key briefly but repeatedly until the desired option is displayed (see /A1 Configuration Parameters Set-Up Table) Press the On/Off key to enter into the desired option Press the SELECT key briefly but repeatedly until the desired configuration parameter is displayed Press the TARE key to save changes and return the balance to normal weighing mode Operation Place the material that needs to be weighed on the weighing pan Close the draft shield Wait until the [U] symbol disappears Read off the value from the display. If using the tare function: Place an empty weighing container on the weighing pan Close the draft shield Wait until the [U] symbol disappears Press the Tare key Open draft shield and place the material to be weighed in the weighing container Close draft shield Wait until the [U] symbol disappears Read off the value from the display Calibration Auto Calibration Press the On/Off Key to switch on the balance Wait until the [U] symbol disappears from the message display Press the TARE key Press the AUTO CAL key. Page 4 of 14

5 Wait until the message display changes from [CAL] to [CAL-100-*] to [TARING] and finally to [GRAMS] to indicate that the auto-calibration process is complete External Calibration 5.5. Maintenance Press the On/Off Key to switch on the balance Wait until the [U] symbol disappears from the message display Press the TARE key Place the standard calibration weight on the weighing pan Wait for the [U] symbol to disappear and the calibration weight value together with [GRAM] to be displayed Press the AUTO CAL key Wait until [XXX.0000] and [CAL-XXX-] are displayed Remove the standard weight Perform the calibration procedure once again if it is to be repeated with a different standard weight See /A2 Calibration Variance Table if calibration variance needs to be modified Disconnect the balance from its power supply before attempting to clean and leave it in its normal operating position Use a clean fine brush to remove any surrounding powder Use a moistened cloth with a mild cleaning agent to clean and remove any spilt material Ensure that the air bubble in the spirit level on the front end of the scale is in the centre of the marked circle. Page 5 of 14

6 5.6. Troubleshooting Fault Possible Cause/s Possible Solution/s - Display previously turned - Press the On/Off Key off by the On/Off key Both displays are blank - Power cord not connected properly - Power cut or an improper voltage supply present - Attach the power cord accordingly - Check if a proper power supply is present - Temporary fault - Disconnect power cord, wait for at least 5 seconds and reconnect [OVER] is displayed Exceeded weighing capacity Reduce the weight - Pan is not properly - Install pan properly installed [UNDER] is displayed - Pan is obstructed - Move balance to a better [GRAM U] continues to be displayed [NO CAL] is displayed during calibration process - Air currents present around balance - Sample not stationary Balance capacity is exceeded location - Move balance to a better location or close all draft shields - Ensure sample is made stationary Use a 50g, 100g or 150g standard calibration weight to complete calibration Page 6 of 14

7 5.7. Flow Charts Installation Start Place balance on a stable surface, away from any vibrations Turn adjustable feet until air bubble in spirit level is in the centre of the marked circle Insert power supply connector in the plug on rear of balance and plug power supply into mains supply Press On/Off key to switch on balance Wait until start-up message and are displayed before use End Page 7 of 14

8 Configuration Start Press Set-Up key briefly but repeatedly until desired option is displayed (see /A1) Press On/Off key to enter desired option Press SELECT key briefly but repeatedly until desired configuration parameter is displayed Press TARE key to save changes and return balance to normal weighing mode End Page 8 of 14

9 Operation Start Using tare function No Place material on weighing pan Yes Place empty weighing container on weighing pan Close draft shield Wait until [U] symbol disappears Press Tare Key Open draft shield and place material to be weighed in weighing container Close draft shield Wait until [U] symbol disappears Read off value from display End Page 9 of 14

10 Calibration Start Press On/Off key to switch on balance Wait until [U] symbol disappears Press TARE Key Yes Performing external calibration Place standard weight on weighing pan No Perform auto calibration by pressing the AUTO CAL key Wait until message display changes from [CAL] to [CAL-100-*-] to [TARING] and finally to [GRAMS] Wait for [U] to disappear and calibration weight value together with [GRAM] to be displayed Press AUTO CAL key Wait until [XXX.000] and [CAL-XXX-] are displayed Remove standard weight Repeat calibration with different standard weight No End Yes Page 10 of 14

11 Maintenance Start Balance needs cleaning No Yes Disconnect balance from power supply Leave balance in its normal operating position and do not tilt sideways Any surrounding powder No Yes Remove using a clean fine brush Any spilt material No Yes Remove using a moistened cloth with a mild cleaning agent Yes Air bubble in spirit level is in centre of marked circle No Manipulate adjustable feet until this is achieved End Page 11 of 14

12 6. Precautions 6.1. Do not install balance near extremes of heat and cold Protect balance from dust and air draughts Keep weighing pan clean and dry to prevent inaccuracies Do not move balance during weighing Ensure that the maximum tolerated weight of 160g is not exceeded during weighing procedures and also when using the tare function Do not leave any items on the balance when this is not in use Only use the balance if the spirit level is correct Adjust the air bubble in the spirit level each time the balance is moved to a different location Avoid static charge buildup of the material to be weighed and of the weighing container When transferring balance to a significantly warmer environment, allow it to acclimatise for approximately 2 hours at room temperature after it has been disconnected from the mains Do not unplug balance as this is designed to be continuously plugged in Ensure that an audible beep is heard whenever one of the keys is pressed if the beeper option is activated. If this beep is not heard, press the key again until the beep is heard. 7. References Denver Instrument Company. AA Operating Instructions. Series Electronic Analytical Balances 8. Appendices /A1 Configuration Parameters Set-Up Table /A2 Calibration Variance Table 9. Revision History Version Number Amendments/ Reasons for change 01 Initial Release Page 12 of 14

13 /A1 Configuration Parameters Set-Up Table Option Function CURRENT DEFAULT FILTER AUTO ZERO BEEPER To display the current selected configuration parameters To reset the balance to the default factory configuration parameters To choose the desired filter settings from [FT FAST] in ideal conditions, [FT NORMAL] in standard laboratory conditions and [FT SLOW] in areas with drafts and vibrations To choose to automatically compensate for zero drift [A-Z ON] or to turn off this correction feature [A-Z OFF] To choose between short beeps [BP SHORT], long beeps [BP LONG] or else to turn off the beeper function [BP OFF] Page 13 of 14

14 /A2 Calibration Variance Table Procedure Message Display Press On/Off key to switch on balance Press AUTO CAL key Press SET UP key repeatedly until calibration value to be modified is displayed for e.g. for 100g CAL CAL-100- Press On/Off key V Press SELECT key repeatedly until desired + or sign is displayed V or V 00.0 Press On/Off key Press SELECT key repeatedly to change first digit (between 0 and 1) Press On/Off key when desired digit is displayed Press SELECT key repeatedly to change next digit (between 0 and 9) Press On/Off key when desired digit is displayed V +/- x0.0 V +/- 1x.0 Repeat the last 4 steps for subsequent digits Page 14 of 14

STANDARD OPERATING PROCEDURE ACB SERIES ACB-600H PRECISION BALANCE

STANDARD OPERATING PROCEDURE ACB SERIES ACB-600H PRECISION BALANCE Ref.. Table of Contents Page 1. Scope 2 2. Objective 2 3. Definitions 2 4. Responsibility 3 5. Procedure 3 6. Precautions 14 7. References 14 8. Appendices 14 9. Revision History 14 Original Authorised