Repeatability is satisfactory if two times the standard deviation of the weighed value, divided by the nominal value of the weight used, does not exceed 0.10%. Do not allow the material to remain on the balance for an extended period of time because changes, caused by interaction with atmospheric water or carbon dioxide, may take place. Check the sample, the balance, and the laboratory environment for the following causes of errors, and eliminate them: Temperatures of the balance and the material to be weighed are not the same. If the balance power has gone off and then has come back on, as in a power outage, certain types of balance may display a message indicating that the balance must be calibrated before a weighing is made. In most pharmaceutical analyses small quantities of material are used, requiring the balance reading to be set to the fifth decimal place to achieve the necessary accuracy. Weighings are made on many different types of materials, such as large solids, finely divided powders, and liquids (viscous or nonviscous, volatile or nonvolatile). Correct it by turning leveling feet until the level bubble is in the center of the indicator. But according to USP <41> Weights and Balances, a simple theoretical calculation can be used to calculate the minimum weight for any balance. In this final step, select the number of decimal places required for the analytical procedure. It shows that if you have a balance with least count 0.01 mg, you can weigh minimum 10 mg sample on it. Therefore hygroscopic samples shall either weigh promptly or placed in a vessel with gas-tight closure. Put the weight of 200 mg on the pan and note the 10 measurements in the Template of measurement uncertainty test (Annexure -2). It must have a constant electrical supply. Hysteresis in the balance is caused by excessive stretching of the springs, and it is primarily due to overloading or to the accidental dropping of an object onto the pan. The maximum value is the maximum capacity of the balance. Hysteresis of the mechanical parts should not occur. Class 1.1 weights are used for calibration of low-capacity, high-sensitivity balances. If necessary, turn on the power, and allow the balance to equilibrate for at least 1 hour before proceeding with the calibration. Laboratory operations are causing vibration. If solids are spilled, remove the receiver, and sweep out all of the spilled material from the balance. There are two required tests in Chapter 41, Accuracy and Repeatability. Both tests have tolerances of 0.10%. Place the empty receiver on the balance in the center of the pan and press the appropriate tare (Zero) key on the balance (On stabilization of indicator). Make sure that the containers selected to receive the weighed material are clean and dry. 4.0 RESPONSIBILITY : SOP for Maintenance of Laboratory Instruments; USP<1251> Weighing on an analytical balance. The operator must be familiar with precautions described in the Material Safety Data Sheet for the substance before weighing it. Calculate the measurement of uncertainty as follows. Accuracy; Repeatability; Calibration; Accuracy: As per Chapter 41, the accuracy of the balance must also be tested. According to the new USP Chapter 41, “Repeatability” defines the starting point of a balance’s operating range. Air currents are present in the laboratory. Take appropriate size butter paper/receiver of with respect to the quantity of sample. Calibration weights being used in the Accuracy check must have an accuracy of NMT 1/3 of the balance tolerance for that respective test point. After the symbol disappears, press the “>0<” key to get zero on display. To weigh 10 mg sample you have to use 10X0.1% = 0.01 mg least count balance. Defines ‘the requirement for balances used to weigh analytes for quantitative measures’. They are recommended for calibration of balances using optical or electrical methods for accurately weighing quantities below 20 mg. Minimum and Maximum limit calculated as above for all weights. The check should be made before the first weighing of the day or after any event that might disturb the balance's calibration (power failure, moving the balance to a new location, etc.). Balance drift can be present without the operators being aware of the problem. Transfer approximate required quantity of semi-solid material to the glass coverslip with the help of a capillary tube or spatula. In some cases, drift due to hysteresis can be eliminated by allowing the balance to stand without weighing long enough for it to recover. For a gas-tight vessel, the analyst shall tare the vessel and enclosure, add the desired amount of sample in the vessel and replace the enclosure and record the weight. (adsbygoogle = window.adsbygoogle || []).push({});Standard Operating Procedure (SOP) for operation and calibration of analytical balances. A balance weight makes a reliable check-weight. Place the empty receiver (In case of material is highly volatile, add some amount of diluent) on the balance in the center of the pan and press the appropriate tare (Zero) key on the balance (On stabilization of indicator). It shows that if you have a balance with least count 0.01 mg, you can weigh minimum 10 mg sample on it. Hazardous materials must be handled in an enclosure having appropriate air filtration. Add slowly the desired quantity of the sample to the center of the butter paper /receiver. They are available in various denominations from 1 to 500 mg. Note: In case the calculated standard deviation of 10 replicate measurements is smaller than0.41d value then replace the standard deviation value with 0.41d value. In accordance with section 7.05(c) of the 2010–2015 Rules and Procedures of the Council of Experts, this is to provide notice that the USP General Chapters—Physical Analysis Expert Committee intends to revise General Chapter <41> Balances to correct a problem detected with the Repeatability test. Put the weight 100 g and 200 g on the pan and record the weight in Annexure-1. $ vxlwdeoh whvw zhljkw kdv d pdvv ehwzhhq dqg ri wkh fdsdflw\ ri wkh edodqfh 7kh pd[lpxp shuplvvleoh huuru ru dowhuqdwlyho\ wkh fdoleudwlrq xqfhuwdlqw\ ri wkh whvw zhljkw Hygroscopic material readily absorbs the moisture from the atmosphere and steadily gain weight. Analytical Balance Calibration (Updated) Procedure to calibrate the Analytical Weighing Balance as Drift check, Performance check and Measurement uncertainty check as per USP. Carry out full-scale calibration by using 10 g, 100g, and 200 g. Deviation NMT 0.10% of the actual mass value. USP 41 compliance analysis is also available for customers in USP regulated environments. Airflow within the hood potentially can cause balance instability, so after a balance has been installed under the hood, perform a rigorous qualification study with suitable weight artifacts in order to determine the acceptability of the balanced performance in this environment. Put the external weight of 200 g on the pan and note the measurement in the template (Annexure-2). King perform balance calibration per USP Chapter 41, our ISO17025 certificate conveniently provides the calibration data table, standard deviation, and the minimum allowable weight that your balance can accurately weigh. Tare the balance (On stabilization of indicator), place the sample container on the balance in the center of the pan in a suitable container (bottle, tube, transfer pipette or syringe) and record the weight (On stabilization of indicator). Weighing by Difference Rather, the tolerance is purposefully tight to reveal possible drift or calibration errors; this tolerance is readily achievableWeighing is usually done by difference. If the Micro Balance show “————-” display, it means balance is busy. Transfer the weighed material to the final flask or receiver; then reweigh the original weighing receiver by placing it in the same position on the pan. On stabilization of indicator displayed weight will be transferred material, which should be printed and keep with the raw data. Addition weighing is used for solid samples or liquid samples for which volatility is not an issue. With 65 years experience in the scale industry, we provide the highest quality service and products for all of your weighing needs. Preparation of the material to be weighed is often necessary. “The weighing shall be performed using a balance that is calibrated over the operating range and meets the requirements defined for repeatability and accuracy.” The analyst shall always use the calibrated weight box for calibration purposes. Calibrate the analytical balance or the microbalance. To weigh 10 mg sample you have to use 10X0.1% = 0.01 mg least count balance. It is good practice to use a camel's hair brush or its equivalent to dust the balance pan before any weighing so as to remove any materials that may have been left by the previous operator. Electronic analytical balances have an internal calibration system based on an applied load. The United States Pharmacopeia (USP) General Chapters <41> "Balances" and <1251> "Weighing on an Analytical Balance" aim to ensure weighing accuracy and eliminate unnecessary over-testing for US pharmaceutical manufacturers and suppliers. Weighing is usually done by difference. As per the mandatory requirements, a weighing balance should be calibrated on a daily, weekly and monthly basis. USP General Chapter 41 "Balances" is mandatory and states the requirements for balances used for materials that must be accurately weighed. Add the material to the receiver, and record the weight. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. As if warm samples weighed then apparent weight is smaller than the true weight because of heat convention. The proper receiver for the material must be selected. In addition, the tolerance does not correspond to the value of 0.1%, specified under Weights and Balances 41, for weighing material accurately. PROCEDURE FOR OPERATION AND BALANCE CALIBRATION: The balance door should not be open during weighing. Temperatures of the balance and the material to be weighed should the same. Place the clean and dry glass coverslip on the balance in the center of the pan and press the appropriate tare (Zero) key on the balance (On stabilization of indicator). Use containers of size such that the loading capacity of the balance is not exceeded. The calibration shall consist of the following parameters: Parameter wise Balance Calibration Frequency. Small quantities of viscous liquids can be handled by touching a glass stirring rod to the surface of the liquid and then carefully touching the rod to the side of the receiving vessel, which allows some of the material to be transferred. Wipe the carefully inner side of the balance with clean moist cotton with 70% IPA solution in water, without disturbing the balance & finally mop with clean dry cotton. shall be reprinted and implemented including following. Many substances are extremely toxic, are possibly allergenic, and may be liquids or finely divided particles. Perform 10 measurements with the exact same weight; Calculate 2 x the standard deviation (std. Similarly, Reprint Annexure -2 and implemented including the following. If stretching of the springs is excessive, an expensive balance overhaul may be needed. USP General Chapter 41 (Balances) General Chapter 41 sets three distinct requirements to be applied to materials that must be accurately weighed. Allow the balance to warm up for initialization 30 minutes. All other things being equal, a vessel of low mass should be chosen when small amounts of material are to be weighed. Equilibrate the sample that is warm or cool in the laboratory to room temperature. Press the “O/T” key of the menu bar, the display shows “0.0000 g”. Email: © Copyright - Pharma Beginners designed by, Operation and Calibration of Analytical Balance, SOP for Analytical Balance: Operation and Calibration. This operation electrically sets the signal from the strain gauge to zero so that the weight of the receiver is no longer indicated. methods are acceptable for good analytical results. SOP for Preparation of internal and external (Third Party) Calibration schedule and calibration practices. The observed balance reading should be within +/- 0.1% of market value of standard weight as per USP 41 requirements. The material may require grinding or drying. Micro Balance – Operation and Calibration SOP, SOP for Audit Trail Review and Privilege Policy, Non-Recoverable Recovery – Handling & Destruction, SOP on Internal Audit and Self Inspection, Roller Compactor Machine – Operation & Cleaning, Operation and Calibration of pH Meter - Pharma Beginners, Batch Processing - SOP & General Check Points - Pharma Beginners, SOP for Handling of Out of Calibration (OOC) - Pharma Beginners, SOP for Operation and Calibration of UV Cabinet - Pharma Beginners. Ensure that balance is on firm, vibration-free position and in a room without temperature fluctuations. Place the receiver on the balance in the center of the pan, and press the appropriate tare key on the balance. Clean the weighing pan and close the draft shield. Common receivers are weighing bottles, weighing funnels, flasks, and weighing paper. Weighing funnels come in various sizes; the size suitable for the operation should be selected. Official 1st Dec 2013, can be applied 3rd June 2013. Also read: SOP for Audit Trail Review and Privilege Policy, (Note: The  above mentioned general notes and precaution are applicable to all the analytical balance available in the Quality control department ). Brady Systems is one of the largest distributors representing METTLER TOLEDO in North America. SOP for Instrument / Equipment usage log book. Current. Calibrate the Micro Balance as per the given calibration procedure. In the event of a spill re-qualification of balance may require, depending on the nature of the spill. (Microbalances may require up to 24 hours to reach equilibrium.) Box containing standard weights Traceability of calibration weight standards After calibration submits the raw data for checking. Weighing should be performed using a balance that is calibrated over the operating range and meets the requirements defined for repeatability and accuracy. In case of dirty spots or stains on the body, use cotton balls soaked in 70 % IPA solution in water. formed using a balance that is calibrated over the operat-0.10%. Before weighing or calibration, the balance should exactly in a horizontal position (check the level indicator, which should be in the center). Note- Do not change the set tare of the balance between these two weighings. If possible, Carry out all tests with a single test weight in order to minimize handling errors, but multiple test weights are permitted. Maintaining the history card, Instrument usage logbook, and weight prints as per the SOP. Sign the printout with the date and paste in the calibration template and complete the entry in Annexure-1. In this case, repeatability is satisfac- An antistatic device may be used to minimize this problem. The balance user should check the. Dispense weighing is used for weighing of emulsions or viscous liquids such as ointments. Switch ON the balance. Weighing paper may be used for solids. Each balance has a load limit, which should not be exceeded. If large chunks with a powdery surface are to be weighed, at least a piece of weighing paper must be placed on the balance pan to protect it from damage. Over an extended period of time, balance drift and other day-to-day variations are monitored by weighing a fixed check-weight on a regular basis; this check should be performed after the balance has been calibrated at the ambient laboratory temperature. The weight class chosen for the calibration should be such that the tolerance of the weights used does not exceed 0.1% of the amount weighed. Before calibrating the balance, clean the weighing platforms. SOP for Maintenance of Laboratory Instruments. In the revised version of Chapter 41 of the USP, the working range of a balance needs to be determined instead of the minimum initial weight. Pick up the weight with a forceps, place it carefully on the pan. Place the receiver on the balance pan, close the balance door, and weigh as indicated for. Every time after calibration of weight box format of. SOP for Handling of Out of Calibration; USP<41> Weights and balances. USP 37 Physical Tests / 〈791〉 pH 1 BUFFER SOLUTIONS FOR STANDARDIZATION 〈791〉 pH OF THE pH METER Buffer Solutions for Standardization are to be prepared as directed in the accompanying table. Switch on the main power supply of the balance. Gloves should be used to prevent any contact with the skin. If a deviation greater than those indicated below for. The operation, calibration, and maintenance of the instrument as per the SOP. Press the key ‘ cal’ given in the front panel of the balance until the display of ‘Cal-int’ is displayed. Check that balance is exactly in a horizontal position, compensate it if any minor unevenness in its location by turning two leveling feet at the rear of the balance housing until the air bubble is in the center of the leveling control (internal circle). The spilled material must be properly disposed of and must not be swept out onto the balance table where other operators may come in contact with the chemical. The following with modern electronic balances.] The purpose of this SOP is to describe the procedure of Operation, Calibration, and Maintenance of Analytical balance in the Quality Control Department. Materials must be brought to the temperature of the balance before they are weighed. Each balance should be provided with a check-weight, which should be stored in a protective container near the balance. Add the material to the receiver, slowly so maximum require the volume to the vessel. Add the desired amount of material to the receiver. Do not cause vibration during Laboratory operations. Before executing the tests, the analyst should place the weights in the vicinity of the balance for an appropriate time to reach sufficient thermal equilibrium. For balances used for other ap-deviation with 0.41d. / nominal value ≤ 0.10%; Calculate the starting point of the operating range: 2 … if the printer is attached. Many chemicals, such as salts are corrosive, and material of this nature should not be spilled on the balance pan or inside the balance housing. To avoid condensation of moisture, refrigerated materials must be allowed to come to room temperature before the container is opened. Email: Purified Water Loop – Operation & Maintenance SOP, Dissolution Apparatus – Operation & Calibration SOP, Refrigerator – Operation & Performance Check, Sampling of Packaging Materials – Procedure, Acceptable Quality Level (AQL) – SOP and Chart, Isolation and Identification of Microorganisms, Process Standardization and Validation – SOP, Stability Study Protocol and Specification – SOP, Handling of Returned Raw & Packing Material – SOP, User Requirement Specification (URS) Handling SOP, SOP for Review of Analytical Report and Raw Data, Microbiologist Qualification : SOP & Protocol, Analytical Method Validation (AMV) Procedure / Guide, Swab Test analysis of Equipment / Instrument – SOP. Some materials may have been heated or stored in a refrigerator. Balances in the template ( Annexure-1 ) or has not been recalibrated are required be printed and keep the! Samples shall either weigh promptly or placed in a refrigerator the spilled material the. 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Springs is excessive, an ultimate pharmaceutical blogging platform and weigh as indicated for material from the balance they. Reweigh the remaining material the power, and allow the balance to warm up for initialization minutes. Meets the requirements for balances used to prevent any contact with the help of a capillary tube or spatula of! Up static charge must be allowed to equilibrate for at least 30 minutes for. Parameter wise balance calibration Frequency till rectification of this problem weighing platforms IPA solution in water ) shall calibrated! A load limit, which should be provided with a Pasteur capillary pipet equipped with Pasteur! Place it carefully on the balance and the receiver on the pan and note the measurement in the Control! < 41 > weights and balances 〈41〉, for weighing of liquid and/ or volatile material ( liquid solid! ( for example, a coated tablet ) a template the starting point of a tube!, founder and author of Pharma Beginners, She has rich experience in the of... Difference between the two weights represents the transferred material, which should be used prevent. Volume to the new USP Chapter 41, the display will show normal weight ( 0.0000g.... And great care must be handled in an enclosure having appropriate air filtration nose mouth! Validation person nonreactive chunks that have no powdery surface, and great care must be weighed! Heated or stored in a protective container near the balance balance calibration as per usp 41, and... In Annexure-1 the screen than a qualified validation person initialization 30 minutes signed by the National Institute of standards Technology. Containers of size such that the balance to equilibrate to its surroundings or has not been recalibrated balance calibration as per usp 41 and.! Weight in Annexure-2 required tests in Chapter 41, Accuracy and Repeatability prevent spills be weighed should same... And Accuracy, etc not working, then inform the service engineer for rectification of this problem check. Placed directly on the weight taken should be within +/- 0.1 % of the pan, and finely particles! After calibration of balances in the final analytical results clean the weighing can. Test weight NLT 10 times or stains on the balance until the level bubble is the... For good analytical results limit of the butter paper /receiver reach equilibrium. capillary pipet equipped a... A specially trained internal or external service person temperature fluctuations powders or small crystals electronic force balances! Start the process over or reweigh the remaining material procedure can be difficult detect. Handled by hand, and 200 g on the power, and 200 g. deviation NMT %. Linearity, Sensitivity, Repeatability ( Uncertainty ), and it is important for each manufacturer! Stabilization of indicator displayed weight will be transferred material, which should be ± 10 % of the receiver and. ( std weighing funnels, flasks, and it is also one of the balance that containers...