Temperature Calibration and Repair Services

Introduction

Fluke Calibration provides calibration and repair services for the former Hart Scientific line of temperature calibration equipment. Calibration and repair services for baths and industrial calibrators are provided in Everett, Washington, while digital thermometer readouts, 4180 and 4181 infrared calibrators, temperature probes (SPRTs, PRTs, thermistors, reference thermocouples) and other reference standards are calibrated and serviced in American Fork, Utah.

Complete an online request for service form.

Need help submitting an online Service Request (RMA)? Watch this brief Quick Start Video » We've also prepared a Getting Started Guide »

For all U.S. temperature instrument repair and calibration needs, contact our customer care center at 877-883-8225 or email us at service@flukecal.com. We will make sure your equipment and technical questions are quickly routed to someone who can provide the service or answers you need.

In Europe, our Primary Temperature Cal Lab provides UKAS accredited fixed-point SPRT calibrations, PRT calibration by fixed-point and comparison, and thermometer readout/temperature probe system calibration options.

Quick links

• Cal lab capabilities »
• Accreditation »
• Cal lab calibration options »
  • SPRT calibration »
  • PRT/RTD calibration »
  • Digital thermometer readout/probe system calibration »
  • Thermistor calibration options »
  • Noble-metal thermocouple calibration »
  • Fixed-point cell calibration »
  • DC resistor calibration »
  • Tips for sending in your thermometer probes for calibration »
• Thermometer readout calibration and repair »
• Industrial calibrator calibration and repair »
• 418X infrared calibrator calibration and repair »
• Calibration bath repair »

Cal lab capabilities

The U.S. temperature calibration program is anchored by the NVLAP accredited Primary Temperature Cal Lab in American Fork, UT (lab code 200348).  The cal lab provides a variety of measurement techniques and solutions to offer temperature calibration solutions from reference level down to the industrial level. Our principal goal is to provide calibration support for all Fluke Calibration temperature probes but we also offer calibration support for many models from other manufacturers.

Our temperature calibrations are backed by the experience of professionals who have participated in the international temperature metrology community over the past four decades. Our experts stay current by actively participating in metrology and standards organizations such as ASTM, NCSLI, MSC, TEMPMEKO, and the ITS Physics Symposium. Their work and contributions to measurement science is evident in the numerous technical papers  they have presented as well as the leadership positions they hold in the international temperature metrology community.  This means that your reference temperature instrument will be calibrated using current industry best practices and backed by industry-leading knowledge and expertise.

Accreditation

In 2002, the U.S. Primary Temperature Cal Lab in American Fork, Utah received NVLAP accreditation for compliance with the ISO/IEC 17025 quality standard for calibration and testing laboratories. This standard has become the most widely accepted worldwide. In 2001 the ILAC (International Laboratory Accreditation Cooperation) agreement made it possible for an accredited calibration performed in one country to be recognized in any other country that is participating in the agreement.

What does our NVLAP accreditation mean for you? It means all of our accredited calibration services have been examined by NVLAP metrology and quality experts and deemed compliant both technically and with respect to quality. You can have confidence that your calibration will be done correctly and the quality standard will be recognized and accepted around the world (download our certificate and complete NVLAP Scope of Accreditation)

Cal lab calibration options

NVLAP accredited calibration services provided by the Primary Temperature Cal Lab are:

• SPRT calibration by ITS-90 fixed-point »
• PRT/RTD calibration »
• Digital thermometer readout/probe system calibration »
• Thermistor calibration options »
• Noble-metal thermocouple calibration »
• Fixed-point cell calibration »
• DC resistor calibration »

Note: the calibration option models listed on this page are for service calibration (i.e. the product is being returned to Fluke for calibration). For calibration of new PRTs, thermistors, thermocouples, fixed-point cells, and dc resistors, refer to the "Models and Accessories" tab of the specific product page for calibration included and calibration options available.

SPRT calibration by ITS-90 fixed-point
Our NVLAP accredited fixed-point calibrations for SPRTs are world-class. Our uncertainties are among the lowest commercially available and our procedures are based on current best practices. We subject each SPRT to stringent quality checks and process controls to ensure the calibration is reliable and accurate. In order to address customers’ needs the SPRT calibration options are divided into three groups:

• Best measurement capability (BMC) »
• Working standard, dual current »
• Working standard, single current »

Note: The calibration option models listed on this page are for service calibration (i.e. the product is being returned to Fluke for calibration). For calibration of new PRTs, thermistors, thermocouples, fixed-point cells, and dc resistors, refer to the “Models and Accessories” tab of the specific product page for calibration included and calibration options available.

Best measurement capability (BMC)
This group represents our BMC uncertainties. Only the best SPRTs qualify for this calibration. To determine if your SPRT qualifies, please contact our customer care center at 877-883-8225.

These calibration models include the following: (1) calibration at two levels of current and extrapolation to zero power, (2) ITS-90 deviation function coefficients and temperature vs. WT90 interpolation tables for the nominal current calibration and the zero-power calibration, and (3) analysis for compliance to ITS-90 criteria for a standard interpolating instrument of the ITS-90.

Working standard, dual-current
This group was created to provide uncertainties low enough for most working laboratories but with specifications that accommodate most SPRTs. These calibration models include the following: (1) calibration at two levels of current and extrapolation to zero power, (2) ITS-90 deviation function coefficients and temperature vs. WT90 interpolation tables for the nominal current calibration and the zero-power calibration, and (3) analysis for compliance to ITS-90 criteria for a standard interpolating instrument of the ITS-90.

Working standard, single current
This family of calibrations was created to provide an economical option for working laboratories that don’t need zero-power analysis and coefficients. Faster turnaround time also makes this an attractive option for many of our SPRT customers. These calibration models include the following: (1) calibration at a single current level, (2) ITS-90 deviation function coefficients and temperature vs. WT90 interpolation tables for the nominal current calibration, and (3) analysis for compliance to ITS-90 criteria for a standard interpolating instrument of the ITS-90.

PRT calibration
Our NVLAP accredited PRT (Platinum Resistance Thermometer) calibrations provide a range of options to address most customers’ needs. We are able to calibrate most PRTs ranging from precision models with α = 0.003925 partially supported sensors, to industrial α = 0.0035 fully supported and thin-film sensors. Odd shaped probes such as some bent-sheath, short length (length < 15 cm (6 in.)), and large diameter (diameter > 8 mm) designs may not be compatible with our calibration equipment, please contact the customer care center at 877-883-8225 to verify calibration feasibility.

We have incorporated several points of analysis in our PRT calibrations to ensure each PRT meets process quality criteria. For example, we measure extra data points to provide over-determined curve fit analysis to verify the coefficients correctly characterize the probe. RTPW (Resistance at the Triple-Point of Water) is measured multiple times during the calibration to ensure the probe is sufficiently stable.

All of the PRT calibration options include a comprehensive calibration report that includes: (1) characterization coefficients (ITS-90 or CVD depending on sensor type), (2) a temperature vs. resistance interpolation table in 1-degree increments and (3) calibration uncertainty at each measurement point.

Our PRT calibration options are divided into the following four groups:

• Precision PRT calibration by ITS-90 fixed-point »
• Precision PRT calibration by comparison »
• PRT (RTD) calibration by comparison »
• 5606, 5607 calibration by comparison »

Note: All PRT calibrations are performed in degrees Celsius only using the ITS-90 temperature scale. For an additional fee, an interpolation table in degrees Fahrenheit is available.

Precision PRT calibration by ITS-90 fixed-point
This calibration option was designed to provide a low uncertainty calibration option for precision PRTs that qualify. Fixed-point cells are used for all above-zero points and a direct comparison method is used at TPW and below-zero measurements to provide low measurement uncertainties.

This PRT calibration option is primarily for the Fluke Calibration 5624, 5626, and 5628 precision PRTs. Other manufacturers’ precision PRTs may be calibrated but they must repeatable (short term repeatability ≤ ±3 mK at 0 °C), 12 in. or greater sheath length, and sheath diameter of ¼ inch (6.4 mm).

Precision PRT calibration by comparison
This calibration group is intended for precision PRTs with α = 0.003925 sensors. Examples of this type of PRT are the Fluke Calibration 5615 and 5616 PRT families. Calibrations are performed by comparison with a reference SPRT in stirred-liquid baths to allow quick calibration turnaround time while also providing low uncertainties.

A list of PRT models calibrated with this option:

• 5608
• 5612
• 5613
• 5613
• 5615
• 5616
• 5618A
• 5618B

PRT (RTD) calibration by comparison This calibration group is intended for industrial PRTs (RTDs) with α = 0.00385 sensors. Examples of this type of RTD are the Fluke Calibration 5622, 5627A, and 5623B models. Calibrations are performed by comparison with a reference SPRT in stirred-liquid baths and hysteresis, repeatability, and insulation resistance are monitored to ensure the RTDs are working correctly.

A list of PRT/RTD models calibrated with this option:

• 5622
• 5623
• 5623A/B
• 5627
• 5627A

5606, 5607 calibration by comparison
This calibration group was created specifically for the Fluke Calibration 5606 and 5607 models to provide an economical, quick turnaround calibration option. These calibrations are performed by comparison with a reference SPRT in Metrology Well calibrators.

Digital thermometer readout/probe system calibration
System calibrations are divided into two categories; system calibration and system verification. The following explains both options.

System calibration
In a system calibration, a full set of as found temperature and resistance data is measured with the readout and probe together. The readout and probe are compared with a reference SPRT in calibration baths. New probe coefficients are calculated based on the as found data and the system is adjusted by entering new probe coefficients into the readout after which as left data is taken. Once calibrated in this manner, the readout and probe cannot be used separately. The following list the system calibration options.

System verification
The system verification calibration is performed by measuring as found data points as selected by you the customer, then typically the readout and probe are separated for individual calibrations followed by system as left data points. If separate readout and probe calibrations are not purchased then only as found data is measured. The following are the system verification calibration options.

Note: Most thermistors are specified to operate from 0 to 100 C. Though we offer temperature points that are below 0 ºC, we do not assume responsibility for any damage that may occur to the thermistor sensor. In some cases the thermistor warranty may be voided as well.

Thermistor calibration options
Thermistors are calibrated by comparison with a reference SPRT in a calibration bath. Included with each calibration is a comprehensive cal report that includes polynomial calibration coefficients and a temperature vs. resistance table printed in 0.1 ºC increments. Calibration uncertainties are listed as well.

Noble-metal thermocouple calibration
Noble-metal thermocouples are calibrated by ITS-90 fixed-point. The thermocouple is measured at multiple fixed-points to allow an over-determined fit to the thermocouple deviation functions as listed in NIST Monograph 175. For Type S and Type R calibrations the calibration data is extrapolated in the range 962 ºC to 1450 ºC. The calibration report includes all pertinent deviation function coefficients, a temperature vs. EMF table, wire homogeneity analysis, and calibration uncertainties.

Fixed-point cell calibration
Our fixed-point cell calibration program is based on current industry best practices. Each calibration consists of direct comparison with a calibrated cell, plateau analysis, purity analysis, and an assigned value considering all pertinent adjustments for pressure, depth, etc. We may be able to provide support for cells manufactured by other companies. Please contact our customer care center at 877-883-3225 for questions.

DC resistor calibration

Tips for sending in your thermometer probes for calibration
Here are some useful tips to consider when sending a probe in for calibration:

• Always check your SPRT or PRT at TPW (Triple-Point of Water) or some other reference temperature before shipment. This applies when the probe is received back from calibration as well to ensure nothing changed during shipment (see Random News article “Closing the Loop” [link])
• Ship SPRTs in their padded wooden case, enclosed in a wooden crate. Cardboard boxes don’t provide enough protection. If possible, hand-carry the SPRT.
• Ship PRTs in padded, rigid cardboard boxes. We recommend at least 2 inches of foam to protect the PRT. Ensure the shipping carton is large enough to allow the tip of the probe to be at least 4 inches from the end of the carton.
• Ensure alumina sheath thermocouples and PRTs are adequately supported for shipment. Alumina sheaths don’t tolerate any type of flexing.

Thermometer readout repair and calibration
Our NVLAP accredited readout calibration service is optimized to provide high quality calibrations with industry leading turnaround times. Our calibrations come standard with as found data, alignment, as left data, and a comprehensive calibration report that includes all measured data and Pass/Fail tolerance status. For questions or help getting your calibration or repair order set up, contact the Fluke Calibration customer care center at 877-883-8225.

Industrial calibrator repair and calibration
All of our industrial calibrator calibrations are Z540 and ISO/IEC 17025 compliant. Our Metrology Well calibrations are NVLAP accredited. We have fine-tuned the calibrator repair and calibration processes to provide high quality calibrations and repairs with industry leading turnaround times. Our calibrations come standard with as found data, alignment, as left data, and a comprehensive calibration report that includes all measured data and Pass/Fail tolerance status. For questions or help getting your calibration or repair order set up, contact the Fluke Calibration customer care center at 877-883-8225.

418X infrared calibrator calibration and repair
Our NVLAP accredited 418X infrared calibrators are calibrated with a true radiometric calibration process using reference standard radiation thermometers. Why is this important? A true radiometric calibration accounts for emissivity to greatly improve calibration results. Our calibrations come standard with as found data, alignment, as left data, and a comprehensive calibration report that includes all measured data and Pass/Fail tolerance status. For questions or help getting your calibration or repair order set up, contact the Fluke Calibration customer care center at 877-883-8225.

Calibration bath repair
For calibration bath repair, please contact our customer care center at 877-883-8225. If possible, our tech support team will help you remotely to fix the bath without sending it in.