Case Study: Turning Sensor Recalibration Costs into a Calibration Laboratory Investment

For many solar companies, irradiance sensors are purchased for one reason: to collect reliable solar measurement data.

They install sensors on-site, use them in research projects, set them up in monitoring stations, and equip them in their solar measurement devices. At first sight, everything looks easy. The sensors are fresh, calibrated, and prepared for work.

However, after one or two years of operation, a crucial question arises:

How is it going to be with all those sensors after the time comes to calibrate them again?

This case study examines a realistic scenario. A company bought several irradiance sensors in 2024. Two years later, the sensors have already been used, and now they need recalibration. The company may entrust the recalibration process to an outside PV calibration laboratory or send them back to SEVEN for recalibration.

Certainly, choosing an external lab initially appears to be the simplest solution.

However, once the company calculates the full cost of recalibrating a large number of sensors, including calibration fees, shipping, customs, downtime, logistics, and future recalibration needs, a different idea becomes much more attractive:

Instead of paying repeatedly for outsourced recalibration, why not build an in-house calibration laboratory?

With the turnkey calibration laboratory and training service provided by BallastCo, businesses will be able to transform a recurring cost of recalibration into a permanent technical asset. It can incorporate such components as equipment, calibration software, certificate creation tools, laboratory set-up services, documentation assistance, indoor/outdoor calibration processes, and training for pyranometer/reference cell calibration. 

Before presenting the case study in detail, the following table provides a simple cost comparison for a company that owns 30 irradiance sensors. It compares the estimated investment required to establish an outdoor calibration setup, an indoor calibration setup, and the cost of sending all sensors to a third-party laboratory for recalibration.

Outdoor Calibration Setup Cost Indoor Calibration Setup Cost Calibration in a Third-party Lab
20.450 EUR 36.650 EUR 460 × 30 = 13.800 EUR

It should be noted that the third-party laboratory cost shown in the table includes only the calibration fee. Logistics-related expenses such as shipping, customs clearance, insurance, administrative handling, and sensor downtime are not included. When these additional costs are taken into account, the total cost of outsourced calibration becomes significantly higher. Therefore, even for companies managing 30 irradiance sensors only, both outdoor and indoor calibration setups can recover their investment after a maximum of two calibration cycles.
 

The Recalibration Challenge Companies Often Overlook

When acquiring irradiance sensors or pyranometers, the purchase cost will become the primary concern. The team assesses the type, range of measurements, accuracy, project needs, and delivery timeframe.

However, recalibration does not stop there.

Professional measurement devices like irradiance sensors and pyranometers require periodic recalibrations to sustain their trustworthiness. That is even more critical in solar power generation, photovoltaic testing, field studies, quality management, and assessment processes.

A small number of sensors can be shipped to an external laboratory without much difficulty.

With an extensive sensor network, everything shifts dramatically; Recalibration will become a whole separate project.

There are sensors to collect, pack, ship, track, recalibrate, receive, inspect, and redeploy. During this time, the company may lose access to important measurement equipment. If the sensors are used in active projects, downtime can create additional pressure.

This is where recalibration becomes more than a technical task. It becomes a cost, logistics, and planning challenge.

The Scenario: A Large Sensor Quantity Reaches Its Recalibration Period


In the given scenario, the company acquired 200 irradiance sensors in 2024.

After about two years of use, it was time to recalibrate the sensors. 

There were two options for the company at that moment:

1. Send the sensors to a third-party PV calibration lab or have them recalibrated by SEVEN.
2. Create their own calibration lab using BallastCo's products and services. 

The first choice resolves the issue at hand.

The second choice not only addresses the current situation but also enables future calibration capabilities.

That difference is what makes the case interesting.

How Outsourcing Recalibration Can End Up Costly

Outsourcing recalibration can seem easy if we only consider its price per each irradiance sensor or pyranometer. However, in reality, the overall cost can be much higher.

For multiple irradiance sensors or pyranometers, outsourcing can consist of:

  • The cost of calibrating each sensor
  • Shipping within the country or abroad
  • Customs duties
  • The cost of packing and shipping
  • The cost of administrative services
  • The waiting period at an external laboratory
  • The cost of returning the sensors
  • The risk of transportation damage
  • Shelf time for each sensor
  • The cost that will need to be paid repeatedly every two years

Once we factor in all these variables, the cost can add up significantly.

More importantly, the organization pays for this cost without acquiring any capabilities to perform recalibration itself.

The next time the irradiance sensors need recalibration, the process repeats itself once more.

The Turning Point: When Recalibration Becomes an Investment Opportunity

There comes a time when the company needs to ask itself a different question.

It isn’t only about:

How much does calibration cost us in this year?

It should also include:

Is the same amount better invested in developing our capacity for calibration?

The company arrived at an answer by considering how many sensors it had coming up for calibration.

Sending a significant number of sensors for recalibration to an independent PV lab or even back to SEVEN may cost more than setting up a calibration lab in-house using the training and equipment package from BallastCo.

This turns the situation upside down.

Instead of seeing recalibration as an unavoidable expense, the company can treat it as the starting point for a new technical asset.

The BallastCo Solution: Build the Laboratory, Keep the Capability

The BallastCo turnkey calibration laboratory solution and training services are intended for companies interested in setting up their own calibration laboratory for pyranometers, reference cells, and solar irradiance sensors.

This service is not just equipment procurement; it includes also the entire practical basis necessary for running a calibration lab.

Depending on the chosen configuration, BallastCo may assist with:

  • Laboratory layout planning
  • Equipment procurement
  • Indoor calibration procedures
  • Outdoor calibration procedures
  • Principles and practice of calibration
  • Traceability and documentation
  • Data acquisition
  • Software for calibration
  • Software for certificate creation and printing
  • Best practices for reproducible results
  • Laboratory operations guidance
  • Theory and practice training

Training may take place at the ArGesim manufacturing site in Türkiye or the customer’s premises.

For a company facing a large recalibration workload, this means the team does not only receive a laboratory. It also receives the know-how to operate it.
 

The Financial Logic: Full Benefit After 100–200 Sensor Calibrations

One of the most compelling aspects of the given situation from the financial perspective is the potential return on investment.

It is possible to receive a return on all expenses associated with setting up the calibration laboratory in BallastCo within approximately 100 to 200 irradiance sensor or pyranometer calibrations.

That number of calibrations will depend on the cost of external calibration services, transportation, customs fees, volume of calibration, and various conditions.

In the current situation, the company has already accumulated 200 irradiance sensors requiring calibration.

This implies that the company will be able to receive its investment in full during the first calibration cycle.

While spending the whole budget on external services, it is possible to spend this money on:

  • Equipment for the company itself
  • Trained employees of the company
  • Software programs used by the company
  • The certification procedure developed by the company
  • The company's calibration process

After that, every additional recalibration can create even more value.

Internal Laboratory vs Outsourced Recalibration
Outsourced Recalibration
Recalibration by outsourcing could prove effective for companies having a limited number of sensors.

However, if a company owns numerous sensors, outsourcing will most likely result in recurring expenses, delays, transportation hazards, and lack of scheduling flexibility.

The company will receive calibrated sensors; however, it will not benefit from developing skills in this domain.

In-House Calibration Laboratory
A calibration laboratory within the company entails an initial cost, but it offers greater control.

The company acquires equipment, software, protocols, documentation capabilities, trained staff, and scheduling flexibility.

For companies having periodic recalibration requirements, this can be the smarter investment.

The Hidden Cost of Waiting

Many companies delay the decision to establish a calibration laboratory because they see it as a future project.

But waiting can also be expensive.

Year by year, there could be additions to the number of sensors used within the company. Sensors bought within various years will definitely require recalibration. In effect, the company will have to bear the costs associated with external calibration on a cyclical basis.

Consider the following scenario:

  • Sensors bought in 2024 will require recalibration once their service periods are over.
  • Sensors bought in 2025 will have to be recalibrated sooner or later.
  • Sensors bought in 2026 will have to be recalibrated at some point.
  • The next project's sensors will add to the cycle.

Without an internal laboratory, every cycle brings the same external cost and logistics burden.

With an internal laboratory, each cycle strengthens the value of the original investment.
 

Operational Benefits Beyond Cost Savings

Cost saving is important, but it is not the only benefit.

An in-house calibration laboratory can also improve speed, planning, quality, and technical independence.

More efficient turnaround time

Recalibration can take place depending on the schedule of the company’s projects instead of being based on the schedule of an external laboratory.

It is highly advantageous for situations where recalibration is required for use at an active PV plant, a solar monitoring system, testing of the production batch, or delivery to customers.

Reduced downtime

If sensors are sent out, they cannot be used.

Having a company laboratory, the processes of recalibration can be organized in batches. This way the company will be able to keep their projects going and manage sensors.

Improved quality control

Calibration will become part of the company’s quality process.

As a result, the technical department will have better control over such things as data collection, document management, certificates creation and general laboratory activity.

Greater independence in technical matters

The company will not have to rely fully on external laboratories for all calibration procedures.

Calibration training from BallastCo provides the customer’s technical staff with knowledge regarding calibration procedure, methodology, indoor and outdoor activities, traceability, documentation, data collection, and certificate creation.

Greater Customer Confidence

With its own calibration capabilities, a company will be able to react faster to customer demands, better help customers understand technical details, and prove greater control over measuring equipment.

The Lessons this Case Study Imparts

The company began with a widespread problem:

There were many irradiance sensors that needed to be calibrated after two years of work.

The straightforward approach would have been to send the sensors either to an outside PV laboratory or to SEVEN company for servicing.

However, taking the costs into account, the company decided that there had to be other solutions as well. And indeed, for large batches of irradiance sensors, outsourcing turned out to be a lot more expensive than establishing your own calibration laboratory.

Having selected BallastCo’s turnkey calibration laboratory system and training course, the company has managed to turn sensor recalibration into a long-lasting internal process.

The message is clear:

If you have many irradiance sensors or pyranometers, don’t treat recalibration as a mere expense. It is your chance to acquire a dedicated calibration laboratory within your company.

Recalibration of sensors owned by companies having only a handful of devices can be outsourced.

For companies with 100–200 or more sensors, the in-house laboratory option becomes much more attractive.

FAQ: Sensor Recalibration Costs and Calibration Laboratory Investment

Why is recalibration of irradiance sensors necessary?
Recalibration is essential to ensure accurate measurements, reliable results, and consistency in solar monitoring, PV testing, and performance assessment.

Why would the recalibration of sensors become costly when outsourced?
The recalibration of sensors through outsourcing entails several factors, which could lead to high-cost estimates such as recalibration charges, shipment expenses, customs, insurance, administration, downtime, etc. The costs would be higher depending on the number of sensors that will undergo calibration.

Should you opt for sending your sensors to a PV lab or creating your own laboratory?
Sending your sensors to an external PV lab will be ideal if the number of sensors is not too many, while creating a laboratory will provide benefits in the long run if the number of sensors is huge or if there is a need to calibrate them repeatedly.

Why will it cost you less to build your own calibration laboratory rather than sending your sensors to SEVEN?
Calibrating large numbers of sensors may require costs such as calibration charges, transportation, customs, logistics, and downtime. In some cases, the total cost can exceed the investment needed to establish an internal calibration laboratory with BallastCo’s equipment and training support.

How can BallastCo assist in the process of setting up a calibration laboratory?
With BallastCo, a company can receive a full turnkey service for calibration lab set up, including the provision of equipment, calibration software, certification program, indoor/outdoor calibration processes, documentation preparation, and training.

How many sensors need to be recalibrated to ensure that the investment pays off?
Depending on the price for external calibration, shipping, customs fees, number of sensors to calibrate, etc., the payback period for investing in BallastCo's training and equipment would be around 100–200 sensors for calibration.

What happens after the first sensors were recalibrated?
The laboratory will keep generating benefits by providing further recalibrations for other sensors produced in different years, future sensor batches, replacement sensors, etc.

Are pyranometers able to undergo calibration within the laboratory alongside irradiance sensors?
Yes. The program of BallastCo enables calibration of pyranometers, irradiance sensors, and reference cells depending on the chosen configuration of the laboratory. 

Does BallastCo have the ability to supply indoor calibration equipment?
Yes. BallastCo is able to supply indoor calibration equipment like a Class AAA sun simulator, sensor delivery device, datalogger, software for calibration, data acquisition software, and software for certification. 

Does BallastCo have the ability to conduct outdoor calibration?
Yes. BallastCo is able to use customized sensor calibration stands and sunlight-based calibration process for outdoor calibration. 

What standards do you apply in your calibration laboratory program?
The standards that are applied by the calibration laboratory program include ISO 9847:2023, IEC 60904-2:2023, IEC 60904-4:2019, IEC 60904-9:2020, and ISO/IEC 17025:2017. 

Would a calibration laboratory work for just one cycle of recalibration?
No. Calibration laboratory represents an investment in technology that can help with future recalibrations, quality control, customer service, tests, and future purchases of sensors. 

Who should consider building an in-house calibration laboratory?
Companies with regular recalibration needs, large sensor quantities, solar monitoring projects, PV testing operations, irradiance sensor inventories, or recurring pyranometer calibration requirements should consider building an in-house calibration laboratory.