As a scientist, a large part of your job is to minimize variability. The calibration process - which is adjusting and validating the accuracy of measuring instruments and equipment to ensure they provide accurate and reliable results - is crucial to achieving this. Taking measurements for data integrity requires careful calibration of what you are trying to measure. Not only that, but calibration is a necessary step in FDA approval and most other compliance regulations. According to Title 21 of the FDA’s Code of Federal Regulations section 820.72, manufacturers need to ensure proper inspection, measurement, and tests to suit the intended purposes and capabilities of producing valid results.


Key Considerations for Calibration

calibration equipment of incubatorsCalibration of laboratory equipment oftentimes connotes an endless endeavor of investigation. As you investigate calibration, it gets more complex the more parameters you add. One of the most important decisions to make is whether to perform it offsite or onsite. Both options have pros and cons, and the choice depends on various factors, including:

  • Type of Instruments
  • Industry Requirements
  • Availability of Resources
  • Level of Accuracy

As you explore different types of calibration - onsite and offsite calibration specifically, these are some of the pros and cons to keep in mind.


Pros of Offsite Calibration

1. Used for Exceptional Cases

In certain situations involving radioactive or biohazardous materials, it is ill-advised to bring the calibration equipment to the facility. To minimize risks to personnel, the environment, and the public, probes are sent out for calibration to a specialized external facility. This ensures that the handling of such hazardous materials is conducted in a controlled and secure manner, reducing the potential for accidents or contamination.

Another unique case benefiting from offsite calibration is continuous particle counters, which work by drawing in air through a sampling inlet and passing it through a detection chamber. They are used to measure the concentration of airborne particles in an environment, such as dust, smoke, pollen, and other types of particular matter. Owning and maintaining this equipment is very expensive and requires careful expertise that only a few people at a calibration site possess. For this reason, most particle counters need to be sent to a special facility to complete calibration.


2. Ideal for Sending Large Volumes of Equipment

If you have a large number of sensors requiring calibration, larger facilities with the capacity to handle such requests can expedite the calibration process, saving you valuable time and resources. These facilities also ensure efficient documentation of the calibration results, any adjustments made, and the standards used. Such documentation is crucial for demonstrating compliance with regulatory requirements, including FDA regulations, GxP guidelines, quality standards, and customer specifications. Having these well-documented records readily available allows for easy audits, inspections, and validation of your processes, ensuring adherence to industry regulations and maintaining the highest quality standards.


Cons of Offsite Calibration

1. Potential for Damage During Transit

During transit, there is always a potential for damage to the probes, which can result in inaccurate calibration and costly repairs. It can result in:

  • Calibration Drift
  • Additional Costs for Insurance and Liability
  • Downtime and Delay
  • Lack of Immediate Feedback
  • Reduced Control Over the Process 

It is important to carefully consider these factors when deciding between offsite vs. onsite calibration options and take appropriate measures to mitigate the risks associated with shipping probes or instruments for calibration.


2. Inaccurate Calibration Due to Environmental Differences

Environmental differences between the calibration facility and the onsite location can affect the effectiveness of the calibration. Changes in altitude or atmospheric pressure can also impact the performance of these instruments, and if the calibration is not done under similar pressure conditions as their typical operating environment, the calibration results may not be accurate in a real-world application. Calibration aims to be as accurate as possible in the situation the equipment and/or sensors are used.


3. Risk of Delays 

There is always a risk of delays during transit, which can result in equipment downtime and lost productivity. Things like delays in send-off and shipping can significantly deter the arrival of your properly calibrated probes, and processing times at calibration facilities can vary. Internal and external communication can also present challenges causing delays in operation, especially on a global scale.


4. Logistical Challenges 

Offsite calibration involves the process of removing and shipping the probe or instrument to a calibration facility, causing downtime and requiring additional resources for uninstallation and re-installation. This can backlog other tasks and lead to the need for replacement probes. Tracking the movement and installation of multiple sensors and devices can become cumbersome and increase the risk of manual errors. These logistical challenges will multiply if there are a large number of sensors and devices involved in the calibration process.


onsite calibration of VOC, particle clounters

Offsite Calibration Presents Costly Challenges

Managing the shipping and logistics of equipment for offsite calibration can be both time-consuming and expensive for customers. Additionally, there is a risk of equipment damage or loss during transit, leading to additional delays and expenses. Moreover, offsite calibration introduces uncertainty regarding calibration accuracy, as customers have limited control and cannot directly observe the calibration process. In summary, offsite calibration poses significant challenges in terms of management and potential costs.


Pros of Doing Calibration Onsite

1. Calibration is Done in the Equipment it is Used in - Increasing Real-Life Accuracy 

By opting for onsite calibration, the calibration process takes place within the precise environment where the sensor is utilized. Consequently, calibration occurs under identical conditions, encompassing temperature, humidity, pressure, and other environmental variables that the equipment will encounter during regular operation. This contextual precision enhances the accuracy of calibration results since the equipment is calibrated in real-life conditions that closely mirror its actual usage environment, reducing potential disparities between calibration and practical operating conditions.


2. Reacts in Real-Time

With onsite calibration, any deviations or inaccuracies in equipment measurements or readings can be quickly detected and corrected or documented in real time. This allows for immediate feedback on the accuracy and reliability of the equipment, and adjustments can be made promptly to ensure accurate results. This is especially important in critical applications where accurate measurements are essential for maintaining quality, safety, or compliance.


3. Better Control Over the Calibration Process

Onsite calibration offers better control over the administrative process, utilizing the "four eyes principle" and real-time offset data upload into EMS or customer quality systems. The four-eye principle involves independent review and verification by at least two individuals, enhancing accuracy, quality control, accountability, and compliance. Proper training, qualifications, and adherence to procedures and standards are vital for effective implementation. With XiltriX, the SafetyNet team will log offsets in the EMS to help you keep an eye on your critical lab assets.


Calibration vs validation white paperCons of Offsite Calibration 

1. Onsite Calibration Isn’t Possible for Each Type of Sensor 

Onsite calibration may not be possible for certain types of sensors, which may require specialized calibration equipment or facilities. Some sensors have technical limitations which may not allow for set up onsite. What’s more, some sensors require very specific certifications to be deemed properly calibrated by industry standards. 


2. Equipment Has to be Made Available for the Calibration Specialist 

Onsite calibration may cause equipment downtime and lost productivity, as the equipment needs to be accessible to the calibration specialist. They will handle equipment setup or disassembly, address any concerns, and provide the necessary information. Being proactive in involving your technician and Lab Manager early in the process ensures task alignment and preparedness for the calibration.


3. Process Can Take Longer 

Calibration is out of your hands so factors such as availability of the calibration specialist, and logistical and operational delays can all play a part in extending the process of proper calibration.


Onsite Calibration Results in Better Accuracy 

Onsite calibration improves accuracy by calibrating in the actual operating environment, reducing shipping and downtime. With XiltriX SafetyNet, the process is managed, relieving the lab manager's stress. It also enables the "4-eye principle" for accurate and consistent calibration with two qualified technicians.



Both sending out probes for calibration and onsite calibration have their advantages and drawbacks. Sending out probes is suitable for exceptional cases, but it can lead to inaccuracies, delays, and logistical challenges. On the other hand, onsite calibration offers increased accuracy, real-time adjustments, and consistency, although it may result in equipment downtime and longer calibration times. Organizations must carefully evaluate these options, considering cost, accuracy, equipment accessibility, time constraints, regulatory compliance, and their capabilities. By making an informed decision, organizations can ensure reliable calibration results that align with their requirements and quality standards.

Ultimately, calibrating onsite is often a better option for cost-effectiveness, time-saving, and resources, as well as ensuring your calibration process complies with your SOPs. As a scientist, the most important factor in your decision-making is achieving accuracy. Onsite calibration ensures more accurate measurements for the integrity of data. Onsite calibration is the clear winner in achieving accurate data as it reduces variability.


Choose XiltriX and Get High-Quality Sensors

XiltriX offers Monitoring-as-a-Service which means they source, install, and maintain all the sensors needed to keep a pulse on your lab operations. XiltriX offers the flexibility to either manage the calibration process for the client or work directly with their preferred calibration vendor, according to the client's preference. In nearly every situation, XiltriX provides built-to-purpose sensors that can be calibrated onsite ensuring higher accuracy. The XiltriX SafetyNet team works as an extension of your team and coordinates directly with your staff to help manage the calibration process, log offsets, and make calibrating the EMS a breeze.