A tachometer is used to measure rotational speed, often expressed in units such as revolutions per minute (RPM). To ensure accurate measurements, the instrument must be calibrated against traceable references.
• Tachometers (optical, contact-based, or digital)
• Typically: 0.5 Hz to 1 kHz
(corresponds to approx. 30 to 60,000 RPM)
• From 2 ms to 2 s
(depending on rotational speed and method)
• Relative uncertainty: ± 0.02%
(depends on measurement range and instrument type)
Calibration is performed by comparing the tachometer reading with a traceable reference frequency. The reference is generated with high precision from a frequency standard system.
The method may be:
• Optical: Light reflection from a marking on the shaft
• Contact-based: Direct measurement via shaft connection
• Simulated signal: Electronic signal emulating rotation
All calibrations are traceable to national and international standards.
All customers have the right to submit a complaint if they are dissatisfied with a calibration service from the Norwegian Metrology Service. Complaints may be submitted in writing or verbally, and are handled impartially and constructively.
Procedure:
Send written complaints to postmottak@justervesenet.no.
Yes. We offer calibration agreements for customers seeking predictability and efficiency. Through such an agreement, we plan calibrations in advance and schedule your equipment for fixed intervals. Delivery time and price are agreed in advance and stated in the order confirmation before work begins. For customers with several similar instruments, we can arrange batch calibration and provide discounts for efficient execution. Please contact us to discuss a customised agreement.
You can order calibration by contacting the Norwegian Metrology Service via email, telephone or our order form. We are happy to help you identify the correct service and provide practical information on how to send in your instrument.
The price depends on the type of instrument and the scope of the assignment. You can find indicative prices in the Norwegian Metrology Service’s price list.
After calibration, you will receive a calibration certificate documenting the measurement results, uncertainty and references used. The certificate also shows traceability to national or international standards and may be used for audits or quality assurance.
The calibration interval should be based on the required accuracy, frequency of use, and the consequences of potential measurement errors. Instruments used frequently, under demanding conditions, or for critical measurements should be calibrated more often than those used rarely or under stable conditions. For instruments used in commercial transactions, legal control intervals may be set by regulation. For other types of instruments, recommendations can be found in Norwegian Accreditation guidelines (e.g. NA-Dok 26a for scales) and international documents such as ILAC-G24.
We recommend assessing your specific needs and contacting us for advice on calibration intervals suited to your instruments and applications.
When you order a calibration, we first agree on the instrument type and the tests required. You then send the instrument to us, or we arrange on-site calibration if necessary. Our experts perform the calibration in accordance with international standards, and you receive a certificate showing the results, uncertainty and traceability. The instrument is then returned to you safely.
Phone:
64 84 84 84
E-mail:
postmottak@justervesenet.no
Contact form:
Fill in our contact form, and we will respond as quickly as possible.
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