A Closer Look Inside Laboratory Products & Services with Sartorius Team Members: Chris Puthoff

Why should I calibrate my laboratory balance?

Calibration = Determination of the difference between nominal (reported) and actual values. Deviations in sensitivity/spanshould be determined at regular intervals to ensure the balance is functioning within specifications. Calibration is requiredanytime the ambient conditions (temperature, humidity, or air pressure) change. Calibration should be performed anytime abalance has been moved or is found out of level. If user or factory-defined tolerance limits are exceeded, the span accuracymust be adjusted. If you’re using an uncalibrated balance, you increase the risk of working with inaccurate measuring results. This incorrect data could affect all processes that follow the initial measurement. Remember, you are using a high precision balance for a reason: you are looking for accuracy which an uncalibrated balance will not provide.


How do I know if I’m using the right laboratory balance for my application?

Validation is intended to determine whether or not your laboratory balance meets a set of initial design requirements, specifications, and regulations. IQ/OQ protocol is used to assist in identifying the proper laboratory balance for yourapplication.

Installation Qualification (IQ), as the name suggests, is carried out after, or concurrently with, the installation of the equipment at the user’s premises. The purpose of the IQ is to provide documentary evidence that the equipment has been built and installed correctly and that all required supporting accessories (printers, foot switches, dispense guns, etc.) are available and connected correctly.

Operational Qualification (OQ) is defined as establishing confidence that the installed equipment is capable of consistently operating within established tolerances. A field service engineer will test all operating functions, such as repeatability, linearity, off center loads, and will issue a calibration certificate for that particular piece of equipment.

Performance Qualification (PQ) is intended to demonstrate compliance with all requirements set forth by the end user. This should be performed by the end user using their SOP for that particular piece of lab equipment. An example of this is a daily weight verification test on a balance. In any case, the PQ can help an end user determine what their calibration cycle should be.

Maintenance Qualification (MQ) is not normally found in other manufacturers’ IQ/OQ/PQ procedures. This section is used by a service engineer to document every time the engineer performs a routine maintenance or repair on the end user equipment.


What is the difference between Preventative Maintenance and Basic Calibration?

Most calibration companies will only place a weight on the balance pan and perform a calibration. They will never look beyond that which might jeopardize the operation of your lab equipment in the future. There are many other tests and adjustments—such as off- center load or linearity—that a qualified factory trained service engineer should perform to ensure accuracy. A proper preventative maintenance will have an engineer inspect the inside of your laboratory balance for foreign objects and debris to help prevent any future failure. The internal weighing system of any balance is a sensitive measurement instrument and debris can impact performance. This will help save on repair costs and downtime and help extend the life of your laboratory balance. Why is it important to have the proper certificates of calibration? Whether your equipment is required to meet certain regulatory factors or not, it is in the best interest of the quality and reliability of your results to maintain proper calibration certificates. When working in a regulated environment, it is required to have a documented calibration audit trail to verify that the equipment is compliant to the specific regulatory guidelines and that the certificates are not expired. Even if the industry you are working in does not require compliance with any of the regulatory guidelines, calibrations with certification are recommended. As a result, this will make determining the proper calibration cycle much easier. The end result will be increased confidence in the accuracy of the results; in addition, the possibility of identifying a potential problem which could result in prolonged downtime can be avoided.


What should I expect from a laboratory balance service provider?

Sartorius recommends calibration and preventative maintenance of your laboratory equipment at least once a year.

A factory trained Sartorius Service Engineer will:

• Determine the best operating environment/location for your balance

• Perform minor repairs on-site

• Perform adjustments as needed

• Perform internal inspection of weighing cell and electronics

• Clean your unit, externally and internally

• Provide end user training