{"id":6801,"date":"2026-07-17T16:56:16","date_gmt":"2026-07-17T16:56:16","guid":{"rendered":"https:\/\/europascal.de\/product\/fluke-calibration-5608\/"},"modified":"2026-10-12T09:24:25","modified_gmt":"2026-10-12T09:24:25","slug":"fluke-calibration-5608","status":"publish","type":"product","link":"https:\/\/europascal.de\/en\/product\/fluke-calibration-5608\/","title":{"rendered":"Fluke Calibration 5608 Precise Reference Thermometer"},"content":{"rendered":"<p>The <strong>Fluke Calibration 5608<\/strong> is a high-precision secondary reference platinum resistance thermometer (PRT) designed for accurate and reliable temperature measurements in calibration laboratories, industrial environments and temperature metrology applications.<\/p>\n<p>With a temperature range from <strong>\u2212200 \u00b0C to +500 \u00b0C<\/strong>, a slim Inconel sheath and excellent short-term stability, the Fluke Calibration 5608 provides a professional solution for temperature comparison calibration, reference temperature measurements and the verification of industrial temperature sensors.<\/p>\n<p>The thermometer features a high-quality platinum resistance sensing element with a four-wire connection, minimizing the influence of connecting lead resistance on measurement results.<\/p>\n<p>One of the most important advantages of the Fluke Calibration 5608 is its small sheath diameter of only <strong>3.18 mm (1\/8 inch)<\/strong>. This slim design reduces stem conduction effects and allows accurate temperature measurements at relatively shallow immersion depths.<\/p>\n<p>The manufacturer specifies a minimum immersion depth of <strong>80 mm<\/strong>, making the Fluke Calibration 5608 particularly suitable for applications where available immersion depth is limited.<\/p>\n<p>Two probe lengths are available: 228.6 mm and 304.8 mm.<\/p>\n<p>The Fluke Calibration 5608 is supplied with an individually measured resistance value at the triple point of water. An accredited calibration with ITS-90 coefficients can be ordered separately.<\/p>\n<p>When combined with a suitable precision thermometer readout, the Fluke Calibration 5608 provides a versatile reference temperature measurement system.<\/p>\n<p>At <strong>europascal<\/strong>, the Fluke Calibration 5608 is an excellent choice for professional temperature calibration and reference measurement applications.<\/p>\n<p>For professional calibration services and metrological traceability, visit the <a href=\"https:\/\/europascal.de\/en\/calibration-services\/\">europascal Calibration Service<\/a>.<\/p>\n<h2>Your Benefits at a Glance<\/h2>\n<ul>\n<li>High-precision secondary reference thermometer<\/li>\n<li>Temperature range from \u2212200 \u00b0C to +500 \u00b0C<\/li>\n<li>Platinum resistance sensing element<\/li>\n<li>Excellent short-term stability of \u00b10.01 \u00b0C<\/li>\n<li>Slim 3.18 mm probe diameter<\/li>\n<li>Minimum immersion depth of 80 mm<\/li>\n<li>Available in two probe lengths<\/li>\n<li>High-quality Inconel sheath<\/li>\n<li>Four-wire resistance measurement<\/li>\n<li>Reduced influence of connecting lead resistance<\/li>\n<li>Suitable for temperature comparison calibration<\/li>\n<li>Suitable for calibration baths and dry-block calibrators<\/li>\n<li>Individual resistance value at the triple point of water<\/li>\n<li>Optional accredited calibration<\/li>\n<li>Optional ITS-90 calibration coefficients<\/li>\n<li>Different connector configurations<\/li>\n<li>Compatible with suitable Fluke Calibration thermometer readouts<\/li>\n<li>Professional calibration support from europascal<\/li>\n<\/ul>\n<h2>Precision Temperature Measurement from \u2212200 \u00b0C to +500 \u00b0C<\/h2>\n<p>The <strong>Fluke Calibration 5608<\/strong> provides accurate temperature measurements over a wide operating range.<\/p>\n<p><strong>Temperature range: \u2212200 \u00b0C to +500 \u00b0C<\/strong><\/p>\n<p>This range covers cryogenic applications, low-temperature calibration, ambient temperature measurements and elevated-temperature industrial applications.<\/p>\n<p>The thermometer can be used in suitable liquid calibration baths, dry-block calibrators and other temperature-controlled environments.<\/p>\n<p>Its precision platinum resistance element provides stable and reproducible resistance measurements.<\/p>\n<p>For accurate temperature indication, the probe must be connected to a compatible precision thermometer readout.<\/p>\n<p>The complete measurement uncertainty depends on the probe calibration, readout performance and measurement conditions.<\/p>\n<h2>Secondary Reference Platinum Resistance Thermometer<\/h2>\n<p>The Fluke Calibration 5608 is classified as a secondary reference platinum resistance thermometer.<\/p>\n<p>Secondary reference thermometers are used in calibration laboratories to transfer temperature values from higher-level reference standards to working thermometers and industrial sensors.<\/p>\n<p>The Fluke Calibration 5608 is particularly suitable for temperature comparison calibration.<\/p>\n<p>A calibrated reference thermometer and a temperature sensor under test are placed in a stable temperature source.<\/p>\n<p>The difference between the indicated temperatures can then be evaluated.<\/p>\n<p>This method is widely used for the calibration of industrial Pt100 sensors, resistance thermometers and temperature measurement systems.<\/p>\n<h2>High-Quality Platinum Resistance Element<\/h2>\n<p>The Fluke Calibration 5608 uses a precision platinum resistance sensing element.<\/p>\n<p>Platinum is widely used in reference temperature measurement because of its reproducible resistance-temperature relationship and good long-term stability.<\/p>\n<p>The electrical resistance of the sensing element changes with temperature.<\/p>\n<p>A compatible thermometer readout measures this resistance and converts it into temperature using the selected calibration characteristic.<\/p>\n<p>For high-accuracy measurements, the resistance-temperature relationship can be determined through calibration.<\/p>\n<p>The resulting calibration coefficients allow the thermometer readout to calculate temperature according to the characteristics of the individual probe.<\/p>\n<h2>Excellent Short-Term Stability<\/h2>\n<p>Temperature stability is an important characteristic of reference thermometers.<\/p>\n<p>The manufacturer specifies short-term stability of:<\/p>\n<p><strong>\u00b10.01 \u00b0C<\/strong><\/p>\n<p>This value demonstrates the excellent reproducibility of the Fluke Calibration 5608 under the manufacturer&#8217;s defined test conditions.<\/p>\n<p>Short-term stability is particularly important when the thermometer is repeatedly used at different calibration temperatures.<\/p>\n<p>A stable reference thermometer helps reduce uncertainty contributions associated with changes in sensor characteristics.<\/p>\n<p>However, short-term stability should not be confused with absolute measurement accuracy.<\/p>\n<p>The actual accuracy of the thermometer depends on its calibration and the connected readout.<\/p>\n<h2>Slim 3.18 mm Probe Diameter<\/h2>\n<p>One of the most important design features of the Fluke Calibration 5608 is its slim probe sheath.<\/p>\n<p><strong>Sheath diameter: 3.18 mm<\/strong><\/p>\n<p>The small diameter provides several advantages.<\/p>\n<p>It allows the probe to fit into narrow calibration inserts and measurement openings.<\/p>\n<p>It also reduces the influence of heat conduction along the probe stem.<\/p>\n<p>This is particularly useful when measuring temperatures in environments where only limited immersion depth is available.<\/p>\n<p>The slim design can also improve thermal response compared with larger-diameter probes under similar measurement conditions.<\/p>\n<h2>Minimum Immersion Depth of 80 mm<\/h2>\n<p>The Fluke Calibration 5608 has a manufacturer-specified minimum immersion depth of:<\/p>\n<p><strong>80 mm<\/strong><\/p>\n<p>Immersion depth is particularly important in precision temperature measurements.<\/p>\n<p>If a thermometer is not immersed sufficiently, heat can be conducted along the probe stem between the measurement environment and the surrounding air.<\/p>\n<p>This effect is commonly known as stem conduction or stem effect.<\/p>\n<p>The resulting temperature difference can introduce measurement errors.<\/p>\n<p>The slim design of the Fluke Calibration 5608 helps reduce this effect.<\/p>\n<p>For demanding calibration applications, the required immersion depth should nevertheless be verified under the actual measurement conditions.<\/p>\n<h2>High-Quality Inconel Sheath<\/h2>\n<p>The <strong>Fluke Calibration 5608<\/strong> features a high-quality Inconel sheath.<\/p>\n<p>Inconel is a nickel-based alloy known for its mechanical strength and resistance to elevated temperatures.<\/p>\n<p>The sheath protects the precision platinum sensing element.<\/p>\n<p>It also provides mechanical durability during repeated use in calibration laboratories.<\/p>\n<p>The material is suitable for many temperature calibration applications involving controlled temperature sources.<\/p>\n<p>Chemical compatibility should be considered when the probe is exposed to aggressive measurement media.<\/p>\n<h2>Four-Wire Resistance Measurement<\/h2>\n<p>The Fluke Calibration 5608 uses a four-wire connection.<\/p>\n<p>Four-wire resistance measurement is particularly important for precision temperature measurement.<\/p>\n<p>In a conventional two-wire connection, the resistance of the connecting leads contributes to the measured resistance.<\/p>\n<p>This can introduce significant errors when measuring a platinum resistance thermometer.<\/p>\n<p>A four-wire connection separates the current-carrying conductors from the voltage-sensing conductors.<\/p>\n<p>This minimizes the influence of lead resistance.<\/p>\n<p>The result is a more accurate determination of the sensing element resistance.<\/p>\n<h2>Calibration at the Triple Point of Water<\/h2>\n<p>The Fluke Calibration 5608 is supplied with an individually measured resistance value at the triple point of water.<\/p>\n<p>The triple point of water corresponds to:<\/p>\n<p><strong>0.01 \u00b0C<\/strong><\/p>\n<p>This temperature is an important reference point in temperature metrology.<\/p>\n<p>The resistance measured at the triple point provides information about the characteristics of the platinum sensing element.<\/p>\n<p>It can also be used as a reference value when evaluating the stability of the thermometer.<\/p>\n<p>The standard resistance measurement does not replace a complete multipoint calibration.<\/p>\n<p>For high-accuracy temperature measurements, an appropriate calibration over the required temperature range is recommended.<\/p>\n<h2>Optional Accredited Calibration<\/h2>\n<p>The Fluke Calibration 5608 can be ordered with an accredited calibration.<\/p>\n<p>Fluke Calibration offers calibration services for secondary reference thermometers.<\/p>\n<p>An accredited calibration provides documented measurement results and supports metrological traceability.<\/p>\n<p>Depending on the selected calibration service, the calibration certificate includes measured values and ITS-90 coefficients.<\/p>\n<p>These coefficients can be entered into a compatible thermometer readout.<\/p>\n<p>This allows the individual resistance-temperature characteristic of the probe to be used for temperature calculation.<\/p>\n<p><strong>Accredited calibration is optional and is not included automatically with the standard probe.<\/strong><\/p>\n<h2>ITS-90 Temperature Conversion<\/h2>\n<p>The International Temperature Scale of 1990, commonly known as ITS-90, is widely used in precision temperature metrology.<\/p>\n<p>A calibrated platinum resistance thermometer can be characterized using ITS-90 calibration coefficients.<\/p>\n<p>These coefficients describe the relationship between the resistance of the thermometer and temperature.<\/p>\n<p>When the Fluke Calibration 5608 is supplied with an appropriate calibration, the coefficients can be entered into a compatible thermometer readout.<\/p>\n<p>This allows temperature to be calculated according to the individual characteristics of the probe.<\/p>\n<p>For the highest measurement accuracy, the thermometer should be used with its own calibration coefficients.<\/p>\n<h2>Intelligent Sensor Connectors<\/h2>\n<p>The Fluke Calibration 5608 is available with different connector options.<\/p>\n<p>Compatible INFO-CON connectors can store calibration coefficients and probe information.<\/p>\n<p>When the probe is connected to a compatible Fluke Calibration thermometer readout, the stored coefficients can be retrieved automatically.<\/p>\n<p>This simplifies the configuration of the measurement system.<\/p>\n<p>It also reduces the risk of errors caused by incorrect manual entry of calibration coefficients.<\/p>\n<p>The availability of this function depends on the selected connector and thermometer readout.<\/p>\n<h2>Available Probe Lengths<\/h2>\n<p>The Fluke Calibration 5608 is available in two versions.<\/p>\n<h3>Fluke Calibration 5608-9-X<\/h3>\n<p><strong>Probe length: 228.6 mm (9 inches)<\/strong><\/p>\n<p><strong>Probe diameter: 3.18 mm (1\/8 inch)<\/strong><\/p>\n<p><strong>Temperature range: \u2212200 \u00b0C to +500 \u00b0C<\/strong><\/p>\n<p>This version is suitable for compact calibration setups and applications requiring a shorter reference thermometer.<\/p>\n<h3>Fluke Calibration 5608-12-X<\/h3>\n<p><strong>Probe length: 304.8 mm (12 inches)<\/strong><\/p>\n<p><strong>Probe diameter: 3.18 mm (1\/8 inch)<\/strong><\/p>\n<p><strong>Temperature range: \u2212200 \u00b0C to +500 \u00b0C<\/strong><\/p>\n<p>This version provides additional length for applications requiring deeper immersion.<\/p>\n<p>Both versions feature the same nominal sheath diameter and temperature range.<\/p>\n<h2>Available Connector Configurations<\/h2>\n<p>The Fluke Calibration 5608 can be supplied with different electrical connections.<\/p>\n<table>\n<tbody>\n<tr>\n<th>Connector Code<\/th>\n<th>Connection Type<\/th>\n<\/tr>\n<tr>\n<td>A<\/td>\n<td>INFO-CON for Fluke 914X<\/td>\n<\/tr>\n<tr>\n<td>B<\/td>\n<td>Bare wire<\/td>\n<\/tr>\n<tr>\n<td>D<\/td>\n<td>5-pin DIN<\/td>\n<\/tr>\n<tr>\n<td>G<\/td>\n<td>Gold pins<\/td>\n<\/tr>\n<tr>\n<td>J<\/td>\n<td>Banana plugs<\/td>\n<\/tr>\n<tr>\n<td>L<\/td>\n<td>Mini spade lugs<\/td>\n<\/tr>\n<tr>\n<td>M<\/td>\n<td>Mini banana plugs<\/td>\n<\/tr>\n<tr>\n<td>P<\/td>\n<td>INFO-CON for Fluke 1523\/1524<\/td>\n<\/tr>\n<tr>\n<td>S<\/td>\n<td>Spade lugs<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The appropriate connector should be selected according to the thermometer readout.<\/p>\n<h2>Compatible Thermometer Readouts<\/h2>\n<p>The Fluke Calibration 5608 is a passive platinum resistance thermometer.<\/p>\n<p>It does not include an integrated display.<\/p>\n<p>A suitable thermometer readout is required to measure resistance and calculate temperature.<\/p>\n<p>Depending on the selected connector, the Fluke Calibration 5608 can be used with compatible instruments such as:<\/p>\n<ul>\n<li>Fluke Calibration 1523<\/li>\n<li>Fluke Calibration 1524<\/li>\n<li>Fluke Calibration 1529<\/li>\n<li>Fluke Calibration 1502A<\/li>\n<li>Other compatible precision resistance thermometer readouts<\/li>\n<\/ul>\n<p>The electrical connection and supported sensor characteristics must be checked before use.<\/p>\n<h2>Temperature Comparison Calibration<\/h2>\n<p>The Fluke Calibration 5608 is particularly suitable for temperature comparison calibration.<\/p>\n<p>A calibrated reference thermometer is placed in a stable temperature source together with the sensor under test.<\/p>\n<p>Both temperature indications are recorded.<\/p>\n<p>The indication error is calculated as:<\/p>\n<p><strong>\u0394T = T_DUT \u2212 T_REF<\/strong><\/p>\n<p>Where:<\/p>\n<ul>\n<li>\u0394T = Temperature indication error<\/li>\n<li>T_DUT = Temperature indicated by the device under test<\/li>\n<li>T_REF = Reference temperature<\/li>\n<\/ul>\n<p>This method is commonly used in professional temperature calibration laboratories.<\/p>\n<p>The measurement uncertainty must consider the reference thermometer, thermometer readout, temperature source and measurement conditions.<\/p>\n<h2>Calibration Baths<\/h2>\n<p>The Fluke Calibration 5608 is suitable for use in compatible liquid calibration baths.<\/p>\n<p>Liquid calibration baths provide stable and relatively uniform temperature conditions.<\/p>\n<p>A calibrated reference thermometer can be immersed together with one or more temperature sensors under test.<\/p>\n<p>The Fluke Calibration 5608 measures the reference temperature.<\/p>\n<p>This allows the indication errors of the sensors under test to be determined.<\/p>\n<p>The slim sheath provides flexibility when positioning the probe inside the calibration bath.<\/p>\n<h2>Dry-Block Temperature Calibration<\/h2>\n<p>The Fluke Calibration 5608 can also be used with dry-block temperature calibrators.<\/p>\n<p>A suitable calibration insert provides a measurement opening for the reference thermometer.<\/p>\n<p>The reference probe is inserted into the dry-block calibrator.<\/p>\n<p>The temperature of the reference probe is measured using a compatible thermometer readout.<\/p>\n<p>This allows the actual temperature to be compared with the indication of the device under test.<\/p>\n<p>The minimum immersion depth and thermal conditions must be considered.<\/p>\n<h2>Temperature Stability Measurements<\/h2>\n<p>Temperature stability is an important characteristic of calibration baths and dry-block calibrators.<\/p>\n<p>The Fluke Calibration 5608 can be used to monitor temperature fluctuations over time.<\/p>\n<p>When connected to a suitable thermometer readout or data acquisition system, the probe provides accurate resistance measurements.<\/p>\n<p>These measurements can be converted into temperature and recorded.<\/p>\n<p>The resulting data can be used to evaluate the stability of the temperature source.<\/p>\n<p>This is particularly useful for laboratory equipment verification and calibration system characterization.<\/p>\n<h2>Technical Highlights<\/h2>\n<table>\n<tbody>\n<tr>\n<th>Feature<\/th>\n<th>Fluke Calibration 5608<\/th>\n<\/tr>\n<tr>\n<td>Product type<\/td>\n<td>Secondary Reference Platinum Resistance Thermometer<\/td>\n<\/tr>\n<tr>\n<td>Manufacturer<\/td>\n<td>Fluke Calibration<\/td>\n<\/tr>\n<tr>\n<td>Temperature range<\/td>\n<td>\u2212200 \u00b0C to +500 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Sensor type<\/td>\n<td>Precision Platinum Resistance Thermometer<\/td>\n<\/tr>\n<tr>\n<td>Short-term stability<\/td>\n<td>\u00b10.01 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Sheath diameter<\/td>\n<td>3.18 mm<\/td>\n<\/tr>\n<tr>\n<td>Available probe lengths<\/td>\n<td>228.6 mm \/ 304.8 mm<\/td>\n<\/tr>\n<tr>\n<td>Minimum immersion depth<\/td>\n<td>80 mm<\/td>\n<\/tr>\n<tr>\n<td>Sheath material<\/td>\n<td>Inconel<\/td>\n<\/tr>\n<tr>\n<td>Electrical connection<\/td>\n<td>Four-wire<\/td>\n<\/tr>\n<tr>\n<td>Lead-wire length<\/td>\n<td>Approximately 1.83 m<\/td>\n<\/tr>\n<tr>\n<td>Triple-point resistance value<\/td>\n<td>Supplied individually<\/td>\n<\/tr>\n<tr>\n<td>Accredited calibration<\/td>\n<td>Optional<\/td>\n<\/tr>\n<tr>\n<td>ITS-90 coefficients<\/td>\n<td>With appropriate calibration option<\/td>\n<\/tr>\n<tr>\n<td>INFO-CON connector<\/td>\n<td>Optional<\/td>\n<\/tr>\n<tr>\n<td>Compatible readouts<\/td>\n<td>Depending on connector<\/td>\n<\/tr>\n<tr>\n<td>Integrated display<\/td>\n<td>No<\/td>\n<\/tr>\n<tr>\n<td>Temperature generation<\/td>\n<td>No<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Fluke Calibration 5608 vs. Fluke Calibration 5609<\/h2>\n<p>The Fluke Calibration 5608 and 5609 belong to the same secondary reference thermometer series.<\/p>\n<p>Both instruments feature precision platinum sensing elements, Inconel sheaths and four-wire connections.<\/p>\n<p>The main differences are temperature range, probe diameter and available lengths.<\/p>\n<table>\n<tbody>\n<tr>\n<th>Feature<\/th>\n<th>Fluke Calibration 5608<\/th>\n<th>Fluke Calibration 5609<\/th>\n<\/tr>\n<tr>\n<td>Temperature range<\/td>\n<td>\u2212200 \u00b0C to +500 \u00b0C<\/td>\n<td>\u2212200 \u00b0C to +670 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Sheath diameter<\/td>\n<td>3.18 mm<\/td>\n<td>6.35 mm or 6 mm<\/td>\n<\/tr>\n<tr>\n<td>Minimum immersion depth<\/td>\n<td>80 mm<\/td>\n<td>100 mm<\/td>\n<\/tr>\n<tr>\n<td>Short-term stability<\/td>\n<td>\u00b10.01 \u00b0C<\/td>\n<td>\u00b10.01 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Sheath material<\/td>\n<td>Inconel<\/td>\n<td>Inconel<\/td>\n<\/tr>\n<tr>\n<td>Four-wire connection<\/td>\n<td>Yes<\/td>\n<td>Yes<\/td>\n<\/tr>\n<tr>\n<td>Accredited calibration<\/td>\n<td>Optional<\/td>\n<td>Optional<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The Fluke Calibration 5608 is particularly suitable for applications requiring a slim reference thermometer.<\/p>\n<p>The Fluke Calibration 5609 is designed for applications requiring higher maximum temperatures.<\/p>\n<h2>Typical Applications<\/h2>\n<p>The <strong>Fluke Calibration 5608<\/strong> is suitable for:<\/p>\n<ul>\n<li>Secondary reference temperature measurements<\/li>\n<li>Temperature calibration laboratories<\/li>\n<li>Platinum resistance thermometer calibration<\/li>\n<li>Pt100 calibration<\/li>\n<li>Temperature comparison calibration<\/li>\n<li>Liquid calibration baths<\/li>\n<li>Dry-block temperature calibration<\/li>\n<li>Temperature stability measurements<\/li>\n<li>Temperature uniformity measurements<\/li>\n<li>Industrial temperature sensor verification<\/li>\n<li>Reference temperature measurement<\/li>\n<li>Quality assurance<\/li>\n<li>Research laboratories<\/li>\n<li>Temperature metrology<\/li>\n<li>Laboratory temperature calibration<\/li>\n<\/ul>\n<h2>Calibration by europascal<\/h2>\n<p>Regular calibration is essential for maintaining reliable temperature measurement results.<\/p>\n<p>europascal provides professional calibration services for temperature measuring instruments and reference temperature measurement systems.<\/p>\n<p>The Fluke Calibration 5608 can be calibrated to determine its resistance-temperature characteristic.<\/p>\n<p>An appropriate calibration provides measurement results that can be used to calculate individual calibration coefficients.<\/p>\n<p>When combined with a compatible precision thermometer readout, the probe forms a reference temperature measurement system.<\/p>\n<p>The overall measurement uncertainty depends on the probe calibration, readout accuracy, sensor stability and measurement conditions.<\/p>\n<p>For professional calibration and metrological traceability, visit the <a href=\"https:\/\/europascal.de\/en\/calibration-services\/\">europascal Calibration Service<\/a>.<\/p>\n<p>europascal also supports customers with the selection of suitable reference thermometers and temperature calibration equipment.<\/p>\n<h2>Why Choose the Fluke Calibration 5608?<\/h2>\n<p>The <strong>Fluke Calibration 5608<\/strong> combines excellent temperature stability, a wide measurement range and a slim probe design in one professional secondary reference thermometer.<\/p>\n<p>Its temperature range from \u2212200 \u00b0C to +500 \u00b0C covers a wide variety of laboratory and industrial calibration applications.<\/p>\n<p>The slim 3.18 mm sheath reduces the influence of stem conduction and allows measurements with relatively shallow immersion.<\/p>\n<p>The manufacturer specifies a minimum immersion depth of 80 mm.<\/p>\n<p>The high-quality Inconel sheath provides mechanical durability.<\/p>\n<p>Four-wire resistance measurement minimizes errors caused by connecting lead resistance.<\/p>\n<p>Optional accredited calibration and ITS-90 coefficients allow the thermometer to be used as part of a traceable reference temperature measurement system.<\/p>\n<p>Different probe lengths and connector options provide flexibility for different applications.<\/p>\n<p>For professional users requiring a precise and stable secondary reference thermometer, the Fluke Calibration 5608 provides an excellent combination of performance, reliability and versatility.<\/p>\n<p>europascal supports customers with reference temperature probes, temperature calibration equipment and professional calibration services.<\/p>\n<p><a href=\"https:\/\/europascal.de\/marke\/fluke-calibration\/\">Further products from Fluke Calibration can be found here.<\/a><\/p>\n<p><a href=\"https:\/\/www.fluke.com\/en-in\/product\/calibration-tools\/temperature-calibrators\/fluke-hart-5608-5609\" target=\"_blank\" rel=\"noopener\">Manufacturer information about the Fluke Calibration 5608 can be found on the official Fluke website.<\/a><\/p>\n<p><a class=\"download-datasheet\" href=\"#\" data-pdf=\"https:\/\/europascal.de\/wp-content\/uploads\/2026\/07\/Fluke-5608-5609-Sencondary-PRT-with-calibration-options.pdf\"><span style=\"color: #0000ff;\"><strong><em>Download Datasheet<\/em><\/strong><\/span><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The <strong>Fluke Calibration 5608<\/strong> is a high-precision secondary reference platinum resistance thermometer (PRT) designed for accurate temperature measurements from <strong>\u2212200 \u00b0C to +500 \u00b0C<\/strong>. Featuring a slim <strong>3.18 mm Inconel sheath<\/strong>, excellent short-term stability of <strong>\u00b10.01 \u00b0C<\/strong> and a minimum immersion depth of only <strong>80 mm<\/strong>, the probe is ideal for temperature comparison calibration, laboratory reference measurements and industrial temperature metrology. Available in lengths of 228.6 mm and 304.8 mm, the Fluke Calibration 5608 features a four-wire connection, multiple connector options and optional accredited calibration with ITS-90 coefficients.<\/p>\n","protected":false},"featured_media":3486,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center 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