- How does imc perform on-site service?
We come with 1 - 2 technicians with 2 - 3 calibration stations. We need an on-site air-conditioned room (doors and passages > 1.20 m) and a work space with a footprint of approximately 2 x 3 m for each calibration station. At a second work station, in parallel with the function testing, we will carry out firmware updates and other agreed work which might be necessary. The calibration certificates and measurement reports will be presented as a pdf. If a printed copy is required, we will deliver this after the work is finished. For receiving a quote, the following information is required:
- Serial numbers of the devices, and any other individual modules
- On-site contact
- A specific date you would like (for staff planning, we'd like 4 weeks lead time)
- What services are wanted? (calibration, adjustment, system inspection, maintenance, software updates, etc.)?
- What time you can work? Early or late shift, Saturday work possible?
- Does the complete measurement chain of our teststation always need to be calibrated?
The process of calibrating a piece of measurement equipment using equipment conformant to higher standards, which in turn is calibrated using equipment conformant to yet higher standards, is known as the calibration chain. The purpose of this calibration chain is to trace the measurement instruments’ accuracy back to national standard reference equipment. This determines a calibration hierarchy. In principle, you could calibrate every individual component and find the total test station measurement chain’s uncertainty in this way; there are mathematical techniques for this purpose. Or you could calibrate the entire measurement chain by replacing your sensor signal with a calibration signal. If the measurement uncertainty of one or more components within the test station’s measurement chain is unknown, the calibration chain to the sensor is interrupted; in this case, it would not be possible to make a reliable statement of the measurement results’ accuracy.
- Can imc calibrate the complete test station measurement chain?
In collaboration with you or with your calibration service provider on location, we can also calibrate the entire test station measurement chain. For test stations provided by imc itself, methods for on-site adjustment of offsets or correction of characteristic curves have generally already been arranged. Upkeep, repair and system maintenance of imc measurement devices, however, can most effectively be performed at imc. For this reason, we recommend that you create maintenance and calibration plans for your test station. When making such plans, please be sure to take any resulting costs into account, for example due to downtime caused by failure, or costs for keeping replacement parts in reserve. We will gladly provide support, both actively and with advice.
- I am unable to uninstall my devices in order to ship them: what should I do?
Contact our hotline, and we will find a solution! We can offer rental systems as interim solutions, for instance, or we can use your planned downtimes, such as company vacations or maintenance periods, to perform service work, including adjustment, system maintenance, and upkeep. We also offer an express version of all service work. We are happy to assist you in composing inspection plans optimized for your circumstances.
- My mobile measurement device runs with a variety of sensors and cable connections; what does that mean for calibration?
In accordance with manufacturer’s specifications, we perform the function test and calibration with imc terminal connectors. Additionally, within the framework of the System Inspection we perform an "all-round" function test "of everything" with any available interconnections specific to the customer, and upon request, if provided by the customer with the pertinent interconnections, we perform "all-round" calibration.
Under some circumstances, the measurement uncertainty is altered by the use of sensor and cabling types not available for calibration of the measurement system. In light of this, you should consider what tolerances are acceptable for your measurement purposes.
- What does calibration entail?
In calibration, the relationship between the measured value of an output quantity and the corresponding value of the measured input quantity is determined under specified conditions. Simply put: comparison with a reference having the same units, which in measurement engineering means determining the measurement deviation returned by measurement equipment. Calibration does not entail technical intervention – such as adjustment – in the measurement equipment. With indicator measurement equipment, calibration determines the deviation between the measured value indicated and the correct value – or the reference value considered correct.
Calibrations are performed in order to ensure that the measurement equipment used indicates values having a known and documented proportionality to an internationally accepted standard for the quantity measured. The goal is that when measurements of the same quantities are performed by different parties, e.g., customer and supplier, comparable results are obtained. The prerequisite for this is that the measurement uncertainty—which is inherent in any measurement—must be known.
Performing calibration leads to results and findings which provide a guide in better understanding and assessing the tolerances of measurement equipment.
- What is an adjustment?
Adjustment refers to the process of adjusting measurement instruments to compensate for known systematic measurement discrepancies. In contrast, then, to calibration, this means manipulating the instrument in a way which produces lasting effects. Note that this renders any previous calibration and its traceability pedigree obsolete! It is then also no longer possible to reconstruct any changes in the instrument's measurement properties.
- What is a legally secure calibration chain?
The process of calibrating a piece of measurement equipment using equipment conformant to a higher standards, which in turn is calibrated using equipment conformant to yet higher standards, is known as the calibration chain. The purpose of this calibration chain is to trace a piece of equipment’s calibration to the national standard.
- How often is calibration necessary?
To get correct measurements in the long term, the test equipment used has to be monitored regularly and calibrated, if appropriate. The time between such calibration treatments is called the calibration interval. We frequently receive questions about the necessary calibration interval for measurement and test equipment. However, there is no unambiguous answer to this question, since a device's state of calibration is dynamic and depends upon the following factors, to name a few: the input quantity and its permissible tolerances, wear and tear on the equipment, stability of previous calibration procedures, measurement precision required and last but not least a company's quality assurance system policies. As a matter of principle, a calibration is valid only at the moment it is performed. Setting deadlines for re-calibration is the responsibility of the equipment user. As a rule, the calibration interval should be designed to optimize the balance between risks and costs. This means that the calibration interval is ultimately the user's own responsibility to determine and monitor. Our recommendation is from 1 up to 3 years. In order to support our customers in determining the calibration interval, we offer consultation from our employees. Our standard statement in our spec sheets is for 1 year.
- What does monitoring of measurement equipment entail?
The goal of a test equipment management system is to ensure the quality of measurements of products and processes. Toward this end, two major issues must be observed:
- The quality of the measurement processes, i.e. how well the measurements are performed,
- The quality of the test equipment, i.e. how well the test equipment is adapted to the measurement task.
To ensure the quality of test equipment, the following must apply:
- Test equipment is clearly labeled
- Equipment performance requirements are stated
- Test equipment is regularly inspected for compliance with defined requirements, i.e. it is calibrated regularly (and adjusted if necessary), (see also Calibration Interval)
- Test equipment used for calibration can be traced to national or international standards (or to documented calibration foundations if no such standards apply)
- Test equipment is treated in such a way as not to compromise its functional properties.
To meet these requirements, a test equipment management system must be introduced which is also compatible with other company goals.
Companies must have test equipment at their disposal for every measurement required, i.e. for every physical unit of relevance. Toward this end, an overview of all test equipment available to the company is needed.
Correct performance of measurements is conditional on all test equipment used being properly calibrated.
- Is monitoring of measurement equipment really necessary?
Management and monitoring of the equipment used serves the following purposes:
- Ensuring the maintenance of measurement equipment
- Use of only appropriate test equipment for the inspection of the conformity of products and processes to requirements
- Ensuring the required precision of test equipment (including of the reference instruments)
- Ensuring the traceability to higher-level calibration standards
- Avoidance of customer complaints due to incorrect measurement results
- Avoidance of rejection of functional products, or of acceptance of defective products for further processing or shipping
- Proof to customers and certification authorities of the conformity of test equipment monitoring systems to requirements
- Overview of all test equipment available/used
- Improvement of employee awareness with regard to performing tests and to treatment of equipment.
Automobile manufacturers and their suppliers, in particular, have been demanding that calibration service providers be accredited in accordance with ISO 17025. Fundamentally, however, what is required is proof of competence: accredited laboratories are such which have proven their capabilities to an independent assessor.
imc is not an accredited calibration service provider. However, by definition we possess the capabilities and the regulations pursuant to TS16949 / QS 9000 do not apply to us.
imc performs calibration with instruments calibrated to the national standards in accordance with ISO 9001. Our service comes standard with a (manufacturer’s) calibration certificate.
The optional calibration reports which include records of measured values conform to the requirements of ISO 17025. DIN EN ISO 9001 only requires a declaration (manufacturer’s calibration certificate) of traceability of the reference equipment used to national standards. By default, we pass the benefit of lower costs to our customers as price savings (extra charge for optional "Certificate with Protocol as per ISO 17025"). The traceability of equipment, archiving of measurement values etc. are governed by ISO 9001:2008, and are regularly monitored by TÜV TÜV Cert Rheinland GmbH. All calibration reports along with measurement values are automatically archived at imc and are optionally available for release (up to 10 years later).
- Is imc an accredited/certified test laboratory?
imc does not operate an accredited calibration laboratory, but we rigorously implement the requirements of ISO 17025 in our own QM system. imc is certified according to DIN EN ISO 9001 since May 1995.
- May only accredited laboratories be commissioned, as required in TS16949/QS 9000?
The requirements stated in QS 9000, ISO/TS16949 and other management systems for accreditation pertain to testing and calibration laboratories commissioned by suppliers in the automobile industry. Accreditation of calibration procedures according to DIN EN ISO/IEC 17025 (general requirements for competence of testing and calibration laboratories), for example, is meant to demonstrate competence, for which accreditation by an independent third party is a (very transparent) method. Alternatively, QS 9000 offers these very suppliers the ability to rely on the manufacturers of test equipment for its calibration. However, these manufacturers need not necessarily be accredited, but can demonstrate their competence in other ways, e.g. by self-declaration, quality assurance agreements or audits. Naturally, the regulation (QS 9000) states this explicitly (QS 9000 3rd edition, 4.10.6 Requirements of Supplier Laboratories).
Note that the applicable standard DIN EN ISO/IEC 17025 does not require accreditation as a test or calibration laboratory.
- Why is imc actually equally well qualified as an accredited test laboratory?
This is expressed in, for instance, DAR-4-EM-03, “Guideline for Traceability in Testing”, in section 3 “Tools for Traceability in Testing – Demonstration of Competence – Measurement Traceability to SI-Units” (excerpt):
The respective requirements set out in EN ISO/IEC 17025 can be considered as fulfilled, if
(3.1.3) calibration or test certificate of the manufacturer of measuring or test equipment is available that demonstrates calibration and traceability to SI Units by means of documented traceable reference standards in line with para. 3.1.5 and using generally recognized methods or demonstrates calibration and traceability to SI Units by a competent calibration laboratory;
(3.1.5) the calibration in the testing laboratory is carried out by generally recognized and specified procedures and appropriate reference standards available that have been calibrated by a competent calibration laboratory outside or inside the testing laboratory;
Items 3.1.3 and 3.1.5 are ensured by imc’s test equipment management.
- According to what standards do you calibrate your instruments?
At the moment, adjustment and calibration operations by imc are steps within an overall production process or a service; this means we have no separate inspection laboratory but rather so-called adjustment and inspection stations. The processes and procedures are set out in a protocol in the test instructions and test planning as elements of our Integrated Management System. All the processes are procedures developed by imc itself. All calibration and adjustment procedures used at imc within the framework of our type testing are developed, validated and optimized for serial inspection with the goal of achieving the greatest precision economically justifiable. In this context, the reports of measurement values are at the same time a certificate and an inspection plan (manufacturer’s specification). It is easy to develop customer-specific inspection plans on this basis; imc is happy to provide support in doing so. In designing the measuring amplifier, the procedures for its adjustment and calibration are also developed at the same time and verified in the type inspection. One part of the procedure is to adjust various parameters due to their dependence on properties of components and on the running temperature; additional parameters such as the sampling rate selected or the selected filtering may not affect the measurement precision according to design targets. The resulting acceptance tests include procedures for the serial production and servicing, which reflect an optimum balance of test precision, standards conformity and economic viability. In our “Calibration” type test, we use the following standards, among others:
The series of standards VDI/VDE/DGQ/DKD 2622: Calibration of measurement equipment for electrical quantities, describes fundamental calibration procedures. DKD 2622 Blatt 5 describes calibration of function generators
DKD 2622 Blatt 11: Calibration guidelines for spectrum analyzers
DKD 2622 Blatt 20 describes the calibration of DC voltage measuring amplifiers Additional standards and guidelines: DKD-R 5-5 regulates the calibration of temperature indicator devices
DKD-R 6-1 regulates the calibration of pressure measurement modules
Power network quality, voltage quality: EN 50160 and DIN 61000-4-30
- Can I only have imc measurement devices calibrated by imc? Can I calibrate an imc measurement device myself? Who may calibrate imc measurement devices?
Naturally, you may commission any accredited calibration laboratory with the calibration. Some equipment users are able to calibrate measurement channels themselves by virtue of their own calibration laboratory, or in some cases, calibration of the entire measuring sequence is carried out prior to each measurement. In such cases we recommend maintenance checkup of the measurement systems every 24 to 60 months, depending on the model and the application. We would be happy to help you with creating inspection plans.
Adjustment and total function testing for imc measurement devices are currently only possible at imc.
- Does calibration also include adjustment/balancing?
Yes. Calibration by imc includes calibration upon receipt (determining actual values, deviations beyond tolerances are noted), a brief function check, adjustment and calibration for release. You receive a manufacturer’s calibration certificate without measurement values (lab reports optionally available). The imc system inspection includes a total functionality inspection from the manufacturing perspective, which is able to reveal certain latent errors. As a customer, you receive a service report. Upon request, the service “only calibration” is available (no adjustment, no subsequent function testing) or only function testing (system inspection). Since 2005, we have included the following items in our price list:
- Calibration (includes: calibration upon receipt, manufacturer’s calibration certificate as per ISO 9001)
- Adjustment (includes: calibration upon receipt, adjustment, calibration for release, manufacturer’s calibration certificate as per ISO 9001)
- System Inspection (includes: system inspection, function checkup, service report)
The imc calibration package which we recommend and which enjoys our customers’ approval consists of the combination of Adjustment and System Inspection .
- Does imc work with any accredited calibration laboratory? Which accredited calibration laboratory would imc recommend?
The reference equipment used by imc is regularly calibrated and, if appropriate, adjusted by accredited calibration laboratories within the framework of our equipment monitoring efforts. Many of our customers have commissioned accredited calibration laboratories with the monitoring of their test equipment. These in turn commission us, as competent manufacturers, with all service work going beyond calibration, such as adjustment, complete function testing, system maintenance, repairs, rental devices etc. Thus we have already been working in a close and cooperative relationship with all of the companies’ calibration providers for many years. Since the competence of all of the accredited calibration laboratories is regularly verified by independent assessors, we are not able to recommend any particular one.
- Can only individual channels be calibrated?
Upon request, we can calibrate only individual channels according to a customer’s inspection plan. The imc DEVICES or imc CANSAS user’s interface allows correction values for the offset or for calculation of special characteristics to be saved for subsequent use in particular applications. We use this capability in our own test station applications, for example. Adjustment of individual channels with permanent recording of correction values in the module storage is generally either not possible or very costly, so only whole systems or modules can be adjusted as a whole. Furthermore, the elaborate test equipment administration for complex measurement systems, in which only individual functions are adjusted or calibrated, deserves mentioning. If you have any special wishes, please feel free to communicate these to our hotline.
- Where can I buy the equipment for calibration or adjustment?
We are happy to offer the appropriate accessories: calibration requires device-specific connection terminals; probably template protocols and an inspection plan. We are also happy to assist you in composing inspection plans and training programs for your personnel.
However, purchase of the necessary equipment for adjustment / overall testing in accordance with manufacturer specifications, and of the associated “know-how” is only economical if you must test very many (> 100) identical systems regularly, or if you have very high logistical costs, for shipping. Typical service work (repair, system maintenance, updating, remodeling, upkeep), however, is still only possible at imc.
- Certification (manufacturer’s calibration certificate): Why are no measurement values stated by channel in the standard package?
In general, a manufacturer's calibration certificate from imc for 1 device as per DIN EN ISO 9001 is adequate for our customers. The calibration process entails calibration upon receipt (determining actual values; the owner is informed of deviations beyond tolerances), a complete function check, balancing, and calibration for release. The owner receives a manufacturer's calibration certificate without measurement values.
The manufacturer's calibration certificate certifies the validity of the calibration in reference to the serial numbers listed (identification of the test object); the serial numbers of the system and of the measurement module are unambiguously correlated to the reports and measured values; the report file headers state the test equipment used along with their imc equipment ID numbers. Optionally, a complete set of reports with measured values and a list of the measurement equipment used can be ordered (measurement values "as received" + "after balancing"). A complete set of reports of this type is needed for trend analysis or for determining calibration intervals, or in the framework of QS-audits, but is not required for a traceable calibration certificate according to ISO 9001ff, for example. We do not include this complete report set as a standard, thus reducing costs for us and our customers. However, the calibration reports with the readings are always archived automatically and are available on file for 10 years. If equipment arrives at our facilities for service work, such as inspections, maintenance or repairing, we additionally provide a service report stating all work performed.
- Is a function test always performed?
The best function test is the system inspection recommended by imc: A function test of the entire device is conducted (e.g., digital input/output, current supply, analog outputs, depending on device configuration). Additionally, each device is subjected to an individual final inspection (function test and a measurement check of individual channels using other calibrators); this final inspection can be made to take account of customer-specific or device-specific prerequisites or conditions (for instance, the characteristics of a special MIC-channel can be checked at this stage). The final inspection is documented internally by imc; the customer receives a service report.
- What does the calibration certificate which comes with new devices mean?
By default, we provide along with every measurement device a manufacturer's calibration certificate with a list of device modules and their associated serial numbers. This certificate is practically a declaration that we have performed calibration traceable back to national standards. The calibration reports with their measurement values are automatically archived and are optionally available (up to 10 years afterwards). The report header states all test equipment used and its respective internal imc ID numbers. Furthermore, our test equipment management conformant to ISO 9001:2008 ensures traceability.
- Why should there be a system inspection in conjunction with every repair or calibration?
The device is returned to the user completely tested (and having been repaired, if necessary)! The imc System Inspection is the best and most reliable 100% function test, which is also able to reveal latent errors. In the course of repairs, re-adjustment is often necessary due to an error found or to a replaced component. Example: power supply unit reported as defective.
Error profile: defective input channels strain the power supply unit.
Plus: DAC (analog output) channel 2 defective.
- Sometimes imc provides a test certificate and no calibration certificate; what is the difference?
With purely digital modules (e.g. DI, DO, ENC, INC, busDAQ ...) or after the test of devices in servicing, for which calibration was not ordered, we certify the function test with a test certificate. This is a voluntary extra service provided by imc, for which there is no legal entitlement.
Measurement values generated in this procedure are generally not archived, but can be recorded for an extra charge; however, no retroactive order of measurement values is possible.
- Why does an imc calibration take so long?
Typically, imc’s processing time for calibration / adjustment, or System Inspection is 7 to 10 business days, due to the high precision of the inspection and to warm-up times. Additionally, shipping paperwork, consultations about any unanticipated repair work etc. all take time. To avoid downtime, it is important that service orders be determined clearly before the equipment arrives at imc. If you suspect that your device is defective, or if you need calibration or a system update or reconfiguration, it is necessary in any case to contact our hotline prior to shipping. The hotline will provide you with an RMA (return merchandise authorization) number.
To make this procedure easier, you can download a form from the Internet to send us by fax or email. Or simply give us a call! Please do not ship any device without previously contacting us and receiving an RMA number. Within the framework of a service contract, definite delivery dates or express service can be arranged!
- Can the report of measured values be provided in electronic format?
Upon request, we can also generate a report as a PDF file. Please note that a complete device report can consist of over 300 pages. Pursuant to a service contract, we can place the report in the Internet for downloading. Toward this end, we will naturally set up a password-protected location.
- The manual states the amplifier uncertainty as <0.05% "of value read from the display"; does this really mean "of the gain range"?
< 0.05% of value read from the display is in this case the correct formulation of the gain error; it refers to the value indicated, not to the input range end value. This means the absolute error is smaller for small values and larger for large values (gain error). The offset error is stated in % of the input range end value. The total error consists of, among other things, the offset- and gain errors.
- I received two calibration certificates, which one is correct?
The imc calibration includes an input calibration (determination of the actual values, for deviations outside the tolerance you will be informed), a short functions test, a renewed balance and a subsequent output calibration. The log record of the initial calibration is marked with "[Calibration certificate number] _C". The log record after the adjustment and recalibration is marked only with the “[Calibration certificate number]".
- Sometimes there is "latitude for interpretation" which raises questions in audits about the statements of the issuance date and the calibration date on the calibration certificate. How are these explained?
An explanation has been provided as a footnote on the calibration certificate since 09/2006: Issue date:
The day on which the calibration certificate is issued. Unless stated otherwise, the issue date is also the date of the last calibration by imc. A duplicate (certified copy) of the calibration certificate is denoted accordingly.
Last calibration on:
If the date of issuance is different from the date of the last calibration, then we additionally state this date on the calibration certificate.
For technical reasons, the set of reports for a measurement system may under certain circumstances consist of multiple reports with differing dates for the respective calibration. The date of the last calibration then corresponds to the issuance date of the last calibration report belonging to the measurement system.
- Why is calibration by imc so expensive?
All of our customers face cost pressures and for this reason the running operating costs for service and system maintenance are an issue. There is often some confusion for the user (whose boss administers the budget) and for the internal or external calibration laboratory. Until 2003 there actually was some confusion affecting our statements and ambiguity in the terminology used (e.g., calibration... what does it mean?)
In response to this situation, we have overhauled our price list and the terminology used in it:
- System calibration = System Inspection + calibration (upon receipt) + Adjustment
- System Revision = Inspection plus maintenance plus update
- System modification = includes System Revision
We also have adopted new service items into our program such as system maintenance, express service, warranty extension and personalized service contracts, and in consequence the whole program has been up and running smoothly for three years, as attested by very positive feedback.
Calibration by imc is no more expensive than by a calibration laboratory, for example. Quite the opposite: by offering the total spectrum of service from one source, we can save you time, money and trouble!
We challenge you to compute the ratio of the last three years of service costs to the purchase costs!
“We protect your investment!” is our proud motto. Test us out!
- Can imc also conduct a DKD calibration?
We cannot provide DKD calibration for measurement devices we supply. However, upon request we can exclusively use calibrators having DKD calibration certificates. Naturally, such a requirement must be expressed when placing an order. When developing our calibration procedures, we give regard to the procedures as described in the DKD, for example.
- Question: Calibration report with "fail" rating
The “input calibration” is a "fail" rating if a channel exceeds a limit value. The “input calibration” describes the current state before adjustment. Then all input channels will be adjusted and checked with the “output calibration”. On the output calibration no "fail" rating should occur, because it describes the current state after the adjustment.
The tolerance values for a channel during the calibration are much more sensitive defined than the tolerance values in the technical data sheet.