Elements In Implementing an Internal Calibration Laboratory

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Calibration is one of the most important aspects when we are engaged directly or indirectly in manufacturing a certain product in terms of measurements.

Almost all of the industries require this service mainly because of quality and safety (and of course including auditor’s requirement).

Because of this, Internal calibration laboratory is mostly established and many calibration laboratories exist to provide their services.

Calibration service allocates a significant amount of a company’s budget and therefore it is a big plus if you consider having an internal calibration laboratory also called in-house calibration to be implemented.

In this topic, I will share my knowledge regarding the elements of an internal calibration laboratory which are aligned in ISO calibration requirements specifically  ISO9001:2015 and ISO17025:2017. You will discover here the needs or requirements in order to implement a calibration system within your company.

I will also share the clauses under ISO9001:2015 where a requirement related to calibration implementation are stated.

A basic Calibration process flow is also presented. This is not a guarantee to be complete but, this is a good starting point to understand and implement your internal laboratory calibration system under ISO calibration requirements.

What are the benefits of Implementing an In-house Calibration Lab?

What is In-house calibration? Basically, it is a calibration system performed or established inside a company’s facility. This is to differentiate it to an external laboratory which is a third-party laboratory. A third party laboratory also has an in-house calibration but in this article, we will concentrate on the company established calibration.

In-house calibration lab executes its own calibration system based on a verified and accepted calibration procedures using traceable reference standard.

If you have a lot of measuring equipment for calibration,  you will save a significant amount of money (in terms of calibration from an outside source and logistics in the long run).

.To verify whether you made the right choice in purchasing a standard, do justification to compare how much you will spend with a single standard in comparison with how much you will pay for a calibration service with the related measurement equipment. See this link for a sample justification.

 

Here is a list of benefits if you have implemented an In-house calibration lab:

  1. You will save time in calibration downtime because you do not need to send your instruments to an outside lab.
  2. Customers have more trust in your performance in terms of monitoring of measurement process.
  3. More capabilities in terms of measurement will be explored.
  4. Calibration support is readily available when needs arise
  5. The possibility of providing calibration support to other locations or departments.
  6. Centralize execution of calibration, better monitoring.  I observed that some companies have their equipment monitored as per department or by the person who utilizes the instruments, it is also their choice of whom they choose to provide calibration service.
  7. Non-Conforming calibration can be detected immediately, therefore, can be isolated or process affected can be informed immediately for proper assessment and disposition of affected product.
  8. An additional safety feature is observed because the transferring part is reduced or eliminated
  9. Reduces the risk of vibrations or other environmental stress that it absorbs during transport thus, increased assurance of stability.
  10. You are implementing most, if not all the calibration requirements of ISO 9001:2015 Standards. See more explanation below.

Some challenges in implementing In-house calibration:

  1. You need to manage a Quality System with wider calibration laboratory processes which include generation and maintenance of calibration procedure, calibration certificates, preparation for a customer audit, audit support to the various area of the industry and more.
  2. A master standard or reference standards are required to be purchased which also needs maintenance and calibration on a given period.
  3. Competent calibration personnel is needed which includes continues training.
  4. You need to maintain the needed laboratory facility in order to support the achievement of  a valid results during calibration. This includes control of environmental conditions. (see element no. 9 below)

Implementation has some challenges, but once the calibration laboratory is established, implementation will become easy, 

Read on to learn and understand the ISO calibration requirements.

Understanding and Implementing ISO 9001:2015 Calibration Requirements

One of the main standard that requires the implementation and proper execution of calibration is ISO9001:2015.

What are the Clauses in ISO9001 where the need for calibration is required, supported and emphasized?

Below are the related clauses for calibration implementation under ISO 9001:2015: Clause 7.1.5 – Monitoring and Measuring Resources and Clause 9.1 – Monitoring, measurement, analysis and evaluation:

  1. Clause 7.1.4 Environment for the operation of processes
    • The organization shall determine, provide and maintain the environment necessary for the operation of its processes and to achieve conformity of products and services. – managing an internal calibration lab or simply calibration implementation  is one of the processes that contribute to product quality and therefore environmental control is necessary (see element no 9 below).
  2. Clause 7.1.5.1 General monitoring and measuring requirements
    • The organization shall determine and provide the resources needed to ensure valid and reliable results when monitoring or measuring is used to verify the conformity of products and services to requirements. (this covers the 12 elements below).
      1. the resources provided are suitable for the specific type of monitoring and measurement activities being undertaken.  (see element no 1 below)
      2. the resources provided are maintained to ensure their continuing fitness for their purpose.  (see element no 12 below)
    • The organization shall retain appropriate documented information as evidence of fitness for purpose of the monitoring and measurement resources. (see element 2 below)
  3. Clause 7.1.5.2 Measurement traceability
    • In order to maintain proper traceability (unbroken chain of comparison) to provide confidence to measurement results, measuring equipments shall be calibrated or verified, or both, at specified intervals, or prior to use, against measurement standards traceable to international or national measurement standards (see element 8 below);
    • properly identified in order to determine their status (see element 6 below);
    • safeguarded from adjustments, damage or deterioration that would invalidate the calibration status and subsequent measurement results. (see element 4 and 6 below)
    • The organization shall determine if the validity of previous measurement results has been adversely affected when measuring equipment is found to be unfit for its intended purpose, and shall take appropriate action as necessary. – this will fall under the process of “handling out of tolerance conditions” which differs to every industry.

      The important thing is that we have a system in place to backtrack and review necessary calibration data when problems are suspected in our calibration results in order to take the necessary actions.

      Read more about this clause in this post. >>5 Mistakes When Using a Calibration Certificate that You Need to Correct

  4. Clause 9.1.1 General requirements for monitoring, measurement, analysis and evaluation
    • The organization shall determine:
      a) what needs to be monitored and measured; (see element 1 below)

      b) the methods for monitoring, measurement, analysis and evaluation needed to ensure valid results; (see element 5 below)

      c) when the monitoring and measuring shall be performed; (see element 1 below)

      d) when the results from monitoring and measurement shall be analysed and evaluated. (see element 13 below)

13 Elements for the Implementation of the Calibration Program in an Internal Laboratory.

1.Calibration Scope

Before we start our calibration project and gather the needed resources, it is important to consider first what is our calibration scope. This is where we can determine our capability of how wide our services can reach and what instruments we can calibrate.

This is the reason why we exist as an internal calibration lab. We will mention here about the parameters that we can calibrate or calibration service that we can provide, the reference standards that we are using with its accuracy or uncertianty value and the reference procedure or methods including reference guides.

When can we perform monitoring and measurement?

As an  in-house calibration lab, we should also determine on when can we execute our calibration job for us to control calibration activities. Below are some reasons why  or when  can we perform calibration:

    • Calibration is performed when a new instrument is  installed or purchased
    • instruments that are mishandled during transfer (example: dropped or fell down)
    • when instrument performance is questionable
    • calibration period is overdue
    • kept in unstable environment for too long (exposed to vibrations or too high/low temperatures)
    • when a new settings or adjustment is encountered
    • when required by a 3rd party audit
    • when required by customers
    • when health and safety requires monitoring
    • when required by a regulatory bodies

If you know your scope and your reason why you perform calibration, you can easily determine and assess the suitability of the reference standards to be used to those instruments that needed calibration. This also means that you are familiar with your reference standards.

For example:

 ABC lab exists to provide a traceable calibration of measuring and test equipment under Dimensional, Pressure, and Electrical that can directly or indirectly affect the quality of our products. The table below details the scope of capabilities and reference standard used.

A sample laboratory scope to show or to determine your capability.

2. Recording System

I am sure before we start sending our instruments to an outside calibration lab, we already have a list of our measuring instruments.

If we have, this list is now our master list for our internal calibration laboratory (if you do not have, you should create one, take inventory of all the instruments for calibration).

It should include all the details of measuring instruments. This is now our starting point,  we have now our inventory, we should determine where they are, who owns the instruments and other details regarding the instruments like the calibration history file.

During this time, also take the time to put proper coding. This is now our monitoring tool. (in my past company, we have a database- the METCAL from Fluke which  automates documentation and monitoring including the generation of calibration certificates).

Before, during and after calibration, a recording is always a must. In calibration (whether internal calibration or external calibration), sometimes recording or documentation has more time to do than calibrating an instrument (so if you are a techy guy that hates writing or documenting a lot, this job will challenge you – just saying:-)) 

The Measurements Data Sheet (MDS) – Record Your Result! 

You should have a form where your results and observations will be placed. I call this form a Measurement Data Sheet (MDS). Others call it Measurement Data record, Calibration record, calibration worksheet, or company calibration form.

Why? Of course, to record and document your calibration execution. But another important reason is that to have proper traceability regarding the performance, not just the execution but all the elements of the calibration system.

Just in case a problem arises regarding the instrument, we can easily trace back who perform the calibration and what procedure has been applied and what data has been recorded etc.

MDS displays all the details regarding the UUC which includes: (Below is a sample Measurement Data Sheet (MDS))

      • Instrument Name
      • Instrument Description
      • Brand/Type/Model/Serial #
      • Equipment code
      • The environmental condition- Temperature and humidity
      • Date Received and Date Calibrated
      • Location of the Instruments
      • Range and Resolution
      • The Standard used during calibration
      • The Methods used in the calibration
      • The owner or department who use the Instrument
      • Results or data
      • The person who performs the calibration
Measurement Data Sheet
Sample Measurement Data Sheet (MDS)

Note that applicable Document Control and Records Control applies to all calibration procedures and forms used and other documents that are part of the calibration system.

Once the data sheet is completed, you can convert it to a Calibration Certificate with almost the same but some added details and more presentable with the title Calibration Certificate (to be more formal and adequate, it should be align with the requirements based on ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories).

To view the ISO 17025 calibration certificate requirements and tips to properly review and interpret the requirements of a calibration certificate, visit this link

        To learn more about the Technical records used in calibration, visit this link >> Calibration Records

 

3. Calibration System (how we execute the internal calibration process)

Calibration system should detect and provide correction to any deficiencies related to calibration. A documented system that monitors and  control all measuring and test devices used in manufacturing a product, used in quality control or inspection operations to ensure conformance at given specifications or requirements.

Once we determine our scope, we will now specify what is the flow of our calibration process,  how we can execute and control calibration job starting from collecting of the UUC to releasing of UUC with calibration certificates.

We will not just receive an instrument then calibrate it immediately. We should have our first step before we proceed for calibration. Every step of a calibration process should be clear to us in order to have a smooth and documented execution.

In order to execute the internal laboratory calibration process properly and to have a clear view, below is a calibration process flow (or a plan) that I implement. You may change it depending on your needs but the steps or requirements should be maintained or more if necessary.

Internal Calibration Process Flow

 

The calibration process presented above is the simplest, we did not consider to put other factors like what if we are not capable in calibrating a certain UUC, what if newly calibrated with an existing calibration certificate or totally damaged equipment?

These questions are usually tackled or solved by considering an additional process, but for simplicity, we will maintain it as is for the sake of this presentation.

4. Receiving of Measuring Instruments

Since we already have the master list, we can notify the owner and wait for them to submit the instruments ( I assume that every UUC has its own user or owner). During this time, just make sure that all instruments that are due for calibration will be collected.

During receiving, make sure that all details are accounted for, below are the main details you need to acquire as a minimum (you need to have a specific form for this):

      1. List all the details about the UUC (name, date,  make, model, serial no.)
      2. Check the status of the Unit Under Calibration (UUC), (this is how we will call here instruments for calibration). Power-up the UUC and perform functionality check;
      3. Check for any defect and missing parts or accessories;
      4. Determine the requirements of the user, this is very important, you may encounter some ranges that you are not capable to perform during calibration where you need to know and inform to the owner.  
      5. Determine and record the calibration interval;
      6. Place the calibration control tag or identification to avoid any confusion. Calibration tag includes below details:
          • your unique indentification number
          • location of calibration
          • date recieved
          • name of the owner

If the organization is small and only one or two persons is handling the instruments or UUC, this is no longer a problem to think but be sure to have complete monitoring of all the instruments under you.

Once the above details are all accounted for,  let the user sign the form for acceptance and that they acknowledge that they are the responsible owner of the UUC.

5. Storage and Handling

Once you already receive the UUC, place them to a designated storage area, see to it that they are protected and with proper separation, label or put a tag to ensure proper identification.

Proper identification and designation will ensure traceability in terms of monitoring the  calibration status while inside the lab. Identification can be  accomplished by placing a calibration tag.

Do not remove tag while it is still for calibration or inside the lab to ensure continuous monitoring of status, also observe proper handling when transferring.  

Check also your storage area, see to it that UUC is protected from any environmental effects such as temperature, humidity or electrostatic discharges. Observe also proper positioning or placing of UUC during staging (vertical or horizontal position) . 

 

UUC Storage Area
Sample UUC (Unit Under Calibration) Storage Area

6. Internal Calibration Procedure (Methods)

This stage is where we determine all the requirements related to the actual calibration of UUC.  After inspecting the received UUC,  we will now determine how we can execute the calibration job.

Actual calibration can be performed or executed by following a documented calibration procedure. Calibration procedures is a controlled document. It is based on:

      • manufacturers manual or equipment manual,
      • based on customer recommendation,
      • based on experience on a similar type of equipment
      • based on published standard documents or guides – this is a must to have or included as a reference, more so  if you are planning to apply for accreditation
      • or a combination of all.

After peforming calibration, it is important to perform a verification. This is to check whether the results we obtain are within the acceptable specifications. How to perform verification? read more in this link >> verification

If you will generate your own calirbation procedure, ensure that is properly validated, meaning you have tested it to be fit for  its purpose and of course, it should be properly documented. Check this link to learn more about validation.

Below are the contents that we should consider in generating a calibration procedure (as a minimum). These requirements are also applicable to ISO 9001 calibration procedure.

      •  Title of the procedure
      •  Scope
      •  References
      •  Required Instruments or reference standards (equipment used)
      •  The Step by Step Procedure (which  includes the Test parameters and tolerances)
      •  The uncertainty of measurements – this is one way to show traceability and confidence to our calibration results, also some auditors are requiring it.

Since it is a controlled document we should not forget to include the Author, revision number, a unique code for this procedure, the revision history and more depending on the format in which your doc control requires you to add. Also, this generated procedure is required to be reviewed once a year or as necessary to ensure the use of an updated one.

7. Labeling and Sealing

Once the UUC is calibrated, labeling or tag should be placed in the UUC as a sign of calibration. This will indicate the status of a calibrated Instrument. Most used labels are stickers which contain below information ( this depends on the laboratory):

      • Name or code of the UUC ( Unit Under Calibration)
      • Certificate number
      • Calibration Date
      • Calibration Due Date
      • The person who did the calibration

Calibration labels should be clearly visible when attached. There are times when a UUC has a limited calibration or a calibration- not-required label, this type of label should be included.

But make sure that there are proper assessment and documentation. Also, regarding the UUC with has a smaller size where it is impractical to put the sticker, we can place it in its box or container.

It is also required to put a tamper-proof seal to protect the newly calibrated UUC from any unauthorized adjustments that can invalidate the calibration settings.

8. Recall System (how can we get them back for recalibration)

Once a calibrated Instruments was returned back to the owner or released to be used again, you should have a recall system to get it back once it is due for calibration ( this is applicable to a very large organization where too many owners are scattered per department or area).

This is one of the most difficult parts, where some owners do not care about their measuring equipment unless they are being caught in an audit.

One best practice to do is to copy their bosses together with the quality team in the email then directly address them during follow up. Also, you can make some kind of a penalty for being overdue.

9. Reference Standards (Equipment)

Reference Standards are the equipment we used to calibrate UUC, we compare and verify the accuracy of the UUC with respect to these reference standards. It has the capabilities of accuracy, stability, range, and resolution for the intended use.

Reference Standards (Master Standards)
Reference Standards (Master Standards)

A reference standard should have the below requirements:

      • As much as possible at least 4 times more accurate than UUC to be calibrated.
      • Must be calibrated  by a laboratory accredited to ISO 17025 with the required Calibration Certificate
      • Traceability to International Standards (BIPM)
      • Properly maintained and verified
      • Properly labelled and identified

Please check this link for traceability

10. Environmental Control

Environmental factors have a great impact on the calibration job. Whenever an environmental condition is not met, the calibration job should be stopped until it returns back to normal.

Normal wherein, for example, a required temperature and humidity range that is prescribed is within the specified range. Since it is critical in our process, it advisable to use a continues recorder, a Thermo-hygrometer, to monitor and record.

Below are some examples of the environmental factors that we need to control:

      1. temperature
      2. humidity
      3. vibrations
      4. dust
      5. lightings

please check this link in my previous post atp learn more about temperature and humidity.

11. Personnel Qualifications

All personnel (calibration technician or engineer) that performs calibration should have proper training, in short, should be competent enough where he can demonstrate the required calibration procedure when prompted.

They must have attended or oriented regarding calibration awareness as the first part of the training or exposure to calibration basics. Calibration awareness is one of the most important training that an organization should take regardless of the area you are in ( like in production, planning, purchasing, and others). Of course, this is under quality surveillance.

Their competency is supported by their qualifications ( experience, education, training, etc). Moreover, all of his training must be included in a record control file for proper monitoring.

The requirements to support Personnel Qualifications are:

    1. Authorizations
    2. Training records
    3. List of responsibilities and Job description
    4. Competency Level

Monitoring personnel qualifications (example: Training)  is a continues process and required to be updated or refreshed regularly.

12. Data Retention (how long do we need to keep a record)

Data retention is important for every records control procedure, in calibration, data retention is very meaningful. Compare to other records, calibration records should be accessible easily even it is an old record, we need to collect and tabulate data specifically the data of reference standards for our history file.

This will provide a reference regarding the performance of a certain instrument, past data will help you to decide on how you adjust or provide a proper disposition specifically in determining the calibration interval of your instrument.

Usually, records retention is 5 years or longer.

13. Quality Control 

What Quality Controls should be implemented to ensure the reliability of the reference standards used?

Reference standards are always used for measurement either inside the laboratory or outside the lab (on-site calibration).  It is exposed to different environments and handling of personnel.

Because of these factors, we must ensure that our reference standards are still in good conditions outside and inside.

Below are the methods that we can implement for this:

  1. Intermediate Check – specifically implemented during  on-site calibration
  2. Preventive Maintenance – a scheduled maintenance
  3. Performing Measurement System Analysis
  4. Re-Calibration and verification
  5. Performing different methods of calibration and verification (replicate test)

Also, measurement results should be monitored and analyzed if  below situation are encountered:

  1. If there is an out of tolerance during calibration and verification or an out of tolerance is suspected.
  2. If a newly instrument or standard has arrived from a third party calibration
  3. During a scheduled maintenance
  4. During the extension of calibration interval
  5. If a new equipment is installed or transfered from a different locations

Conclusion

Internal calibration which is also known as In-house calibration is one of the most important processess within a company in order to provide a good product or services, thus, implementation requires deep knowledge and dedication.

In this article, I have presented and explained the following:

  1. The Benefits of implementing an in-house calibration laboratory;
  2. Some Challenge that you will enocounter during implementation;
  3. Understanding and implementing the requirements of ISO 9001:2015 related to calibration
  4. The 13 elements that you need to have when implementing in-house calibration laboratory.

Calibration involves so many factors to determine and consider when implementing such as:

    • How to Handle out of tolerance calibration results?
    • What to prepare during customer audits/internal audits?
    • How to determine the calibration intervals?
    • What will you do if you have a lot of overdue for calibration?

A smooth flow of operations is the result of a planned and documented calibration system, there should be a continuous improvement of every aspect to adapt to the ever-changing requirements and needs as per the International Standards like ISO 9001:2015 and ISO 17025:2017.

What do you think?

Thank you for visiting my site, please leave a comment and subscribe.

Edwin

24 Responses

  1. Serjy
    | Reply

    Can you talk about BS50504 standard for calibration of welding machines.

    • edsponce
      | Reply

      Yes, I will consider if i have the resources. do you have a copy of the BS 50504 standard?

  2. Alvin
    | Reply

    Hi sir. Thanks for this post. We are planning to have an internal calibration laboratory in our company and with this post we can easily plan and justify our initiative by following your posts. Thanks a lot

    • edsponce
      | Reply

      Hi Alvin,
      You are welcome. I am very happy knowing that you are using this post as a guide. Hope that it can help you in more ways. I would be glad to know the outcome of your calibration journey in establishing your Internal Calibration Lab. Please do not hesitate to provide more feedback.

      Best regards,
      Edwin

  3. Ich
    | Reply

    Thanks you very much sir for the post.

    • edsponce
      | Reply

      Hi Ich,
      You are welcome. Thank you for reading my post. Please feel free to comment for any related concerns.

      Best Regards,
      Edwin

  4. edmar
    | Reply

    thank you sir..an apportunity to enhance and effective internal cal lab

    • edsponce
      | Reply

      Hi Edmar,
      You are welcome. Thank you for reading my post.

      Best regards,
      Edwin

  5. azwan
    | Reply

    what is the suibtable size of lab for in house calibration?

    • edsponce
      | Reply

      Hi Azwan,
      Thank you for visiting my site.

      There are no requirements for the size in any calibration lab. The size of a lab depends on:

      1. The scope of your capability or the number of parameters that you can calibrate.
      2. The number or size of your equipment or reference standards,
      3. The budget that a lab can provide
      4. The size of the company and the number of users or instruments it serves.

      The things that you need to consider when looking for a laboratory room are:

      1. Ensure that no cross-contamination is seen or experience.
      2. Instruments should be protected and staged properly.
      3. Some instruments or reference standards need to have a separate space because they are sensitive to temperature or humidity or other environmental factors. This can contribute to error in results and therefore needs to be separated. Example, temperature instruments cannot be mixed with the dimensional instruments.
      4. You need also to consider that the lab must have a stable and clean environment.
      5. There is no confusion on what parameters to be calibrated. There is enough space for proper separation or segregation.

      Hope this helps,
      Edwin

  6. Vinod Choudhary
    | Reply

    Thanks a lot sir for this useful information.

    • edsponce
      | Reply

      Hi Mr. Vinod,

      You are welcome.
      Thank you for giving time reading my long article.

      Best regards,
      Edwin

  7. John Getalla
    | Reply

    Thanks Edwin, This a very interesting article to re-visit. I’ve been thinking about the sealing requirement “to put a tamper proof seal on the intrument to safeguard from adjustment which may invalidate results” ; any suggestion on how to do this in an industrial process environment wherin intrument/gauges were mostly subjected to low/high temp, dry/wet and CIP conditions.

    • edsponce
      | Reply

      Hi John,

      Thank you for reading my post.
      I have seen a tamper-proof sticker that can withstand a harsh environment that you have specified but I do not know any suppliers. What we usually used like for example to some pressure transmitters, valves or gauges is the round lead seals with wires. The only way to access the instrument in this seal is to cut the wires. You can see this in this link>> Lead seal

      Let me know if it suits your need.

      Thanks and regards,
      Edwin

  8. Charlie
    | Reply

    Sir. Good day. Because of your post I am considering to revise our in-house procedure. Thank you so much sir.

    • edsponce
      | Reply

      Hi Charlie,

      You are welcome. I am glad to know that my post have helped you in some way.
      I appreciate your time reading my post. For any other related concern, please feel free to comment.

      Thanks and regards,
      Edwin

  9. Charlie
    | Reply

    Sir, we had audit findings from one of our customers on validation of our autoclave. Sir what is the difference of validation and verification and how do you perform validation of instrument. We already have valid plan but this will be the first time that i will be using it. Thanks.

    • edsponce
      | Reply

      Hi Charlie,

      Thanks for reading my post.

      Verification is the confirmation that the final results of your measured value are within the specified tolerance or specifications.

      For example, with your autoclave, you perform a verification with its temperature. As per your process tolerance, the reading should be within +/-5 Deg C. If your result is outside this tolerance limits, then it is FAIL and needs adjustment.

      Validation is a more thorough process, it involves many processes. Validation is used to ensure that a given process, equipment, or a procedure is fit for its intended purpose.

      Using again your autoclave as an example:

      First, we will perform functional checks, physical check and the completeness of its accessories and parts.
      Second, we will perform calibration of its pressure and temperature parameters, and afterward verification. Adjustment is done when needed.
      Finally, you will need to perform an actual run or test for your product and see if it meets your specifications.

      All these are documented and signed for approval and release by the authorized persons.

      I have created a separate article about the difference of calibration, verification and validation in this link >>> calibration, verification, and validation

      To supplement your procedure, you make check this guide from EURACHEM for method validation>> The Fitness for Purpose of Analytical Methods.

      Best regards,
      Edwin

  10. Charlie
    | Reply

    Thank you for the information sir edwin.

    • edsponce
      | Reply

      Hi Charlie,
      You are welcome. Happy to help.

      Best regards,
      Edwin

  11. Simphiwe dladla
    | Reply

    Thanks Mr
    Powerful information

    • edsponce
      | Reply

      Hi Simphiwe,

      Thank you for reading my post. I am glad you liked it.

      Best regards,
      Edwin

  12. Ariel
    | Reply

    Hi Edwin,

    Thanks for sharing this post and this information will help me to improve our internal calibration.

    Thanks & Regards,
    Ariel

    • edsponce
      | Reply

      Hi Ariel,
      You are welcome. Happy to know you have learned something in this article.

      Appreciate your comment.

      Thanks and regards,
      Edwin

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