The Fluke Calibration 2638A Hydra Series III is a versatile multi-channel data acquisition system designed for temperature measurements, electrical measurements, data logging and automated test applications. It combines precision measurement capabilities with flexible input configurations, making it suitable for calibration laboratories, industrial quality assurance, process monitoring, research and production testing.

With up to 66 differential input channels, scan rates of up to 46 channels per second and support for thermocouples, resistance temperature detectors (RTDs), thermistors, DC voltage, AC voltage, resistance, frequency and DC current, the Fluke Calibration 2638A provides a comprehensive solution for demanding multi-channel measurement applications.

The system is designed to acquire large quantities of measurement data reliably while providing convenient configuration, visualization and storage functions. Its color display allows users to monitor measurement values and trends directly on the instrument without requiring a computer for every measurement task.

The Fluke Calibration 2638A Hydra Series III can be configured with different input modules according to the application. This modular architecture makes it possible to optimize the system for temperature measurements, electrical measurements or mixed sensor configurations.

For professional calibration services and metrological traceability, visit the europascal Calibration Service.

Your Benefits at a Glance

• Up to 66 differential input channels
• Up to 120 single-ended input channels
• Scan rates up to 46 channels per second
• Flexible modular input architecture
• Supports thermocouples
• Supports RTDs and PRTs
• Supports thermistors
• DC voltage measurement
• AC voltage measurement
• DC current measurement
• Resistance measurement
• Frequency measurement
• Integrated mathematical functions
• Large color graphical display
• Real-time trend visualization
• Integrated data logging
• Internal memory for measurement data and setup files
• USB memory support
• LAN communication
• USB communication
• Flexible trigger functions
• Alarm outputs
• Suitable for temperature mapping
• Suitable for environmental chamber testing
• Suitable for process monitoring
• Suitable for research and development
• Professional calibration support from europascal

Flexible Multi-Channel Data Acquisition

The Fluke Calibration 2638A is designed for applications where many measurement points must be monitored simultaneously or sequentially.

Depending on the installed input modules and wiring configuration, the instrument supports up to:

66 differential channels

or up to:

120 single-ended channels

This high channel density makes the Fluke Calibration 2638A particularly suitable for applications involving large numbers of sensors.

Multiple channels can be configured individually for different measurement functions.

For example, one system can simultaneously monitor thermocouples, RTDs, voltage signals and resistance values.

This flexibility reduces the need for multiple separate measuring instruments.

Scan Rates up to 46 Channels per Second

The Fluke Calibration 2638A provides scanning speeds of up to:

46 channels per second

A high scanning rate is useful when many measurement channels must be monitored within a short period.

This capability makes the instrument suitable for dynamic test applications as well as large multi-channel measurement systems.

The optimum scan rate depends on the selected measurement function, integration time, channel configuration and required measurement accuracy.

For high-precision measurements, a slower measurement configuration may be preferable.

Thermocouple Measurements

The Fluke Calibration 2638A supports a wide range of thermocouple types.

Supported thermocouple types include commonly used industrial sensors such as:

• Type B
• Type C
• Type E
• Type J
• Type K
• Type N
• Type R
• Type S
• Type T

Thermocouples are widely used because they cover broad temperature ranges and can withstand demanding industrial environments.

The Fluke Calibration 2638A measures the thermoelectric voltage generated by the thermocouple and converts the signal into a temperature value according to the selected thermocouple type.

Accurate thermocouple measurements require correct reference junction compensation.

The input modules provide cold junction compensation for thermocouple measurements.

For demanding applications, thermocouple homogeneity, reference junction accuracy, connection materials and measurement uncertainty should also be considered.

RTD and PRT Measurements

The Fluke Calibration 2638A supports resistance temperature detectors and platinum resistance thermometers.

RTDs are widely used for precise industrial temperature measurements because of their excellent repeatability and long-term stability.

The system supports common platinum resistance thermometer characteristics.

Depending on the selected configuration, resistance sensors can be connected using two-wire, three-wire or four-wire measurement techniques.

For precision measurements, four-wire resistance measurement provides the best compensation for connecting lead resistance.

Three-wire measurement is widely used in industrial applications because it provides good compensation while requiring fewer conductors.

The appropriate measurement configuration should be selected according to the required measurement accuracy and sensor design.

Thermistor Measurements

The Fluke Calibration 2638A can also be used with thermistors.

Thermistors provide high sensitivity to temperature changes and are frequently used for precise measurements over limited temperature ranges.

The high resistance measurement capability of the 2638A allows compatible thermistors to be integrated into multi-channel temperature measurement systems.

This makes the instrument suitable for applications where different temperature sensor technologies must be measured within the same test setup.

DC Voltage Measurements

The Fluke Calibration 2638A provides precision DC voltage measurement capabilities.

DC voltage measurements are useful for monitoring:

• Sensor output signals
• Process transmitters
• Power supplies
• Battery systems
• Analog control signals
• Laboratory experiments

Different measurement channels can be assigned individual voltage ranges according to the connected signal.

The instrument automatically records the measurement results together with channel and time information.

AC Voltage Measurements

Unlike many temperature-only scanners, the Fluke Calibration 2638A also supports AC voltage measurement.

This provides additional flexibility for general-purpose data acquisition and electrical testing.

AC voltage measurements can be combined with temperature and other electrical measurements within the same automated test sequence.

This makes the Hydra Series III suitable for applications extending beyond conventional temperature scanning.

DC Current Measurements

The Fluke Calibration 2638A supports DC current measurement.

Current measurement is particularly useful when monitoring industrial transmitters and control signals.

Typical process instrumentation frequently uses current signals such as:

4 mA to 20 mA

By measuring these signals together with temperature or voltage channels, the Fluke Calibration 2638A can be used to evaluate complete measurement chains.

Appropriate connection and input protection requirements must always be observed.

Precision Resistance Measurement

Resistance measurement is another important capability of the Fluke Calibration 2638A.

It allows the system to measure resistive sensors and electrical components.

Resistance measurements are also fundamental for RTD and thermistor temperature measurements.

Depending on the measurement configuration, two-wire, three-wire and four-wire resistance measurements can be performed.

Four-wire measurement minimizes the influence of connecting lead resistance and is therefore preferred for precision resistance measurements.

Frequency Measurement

The Fluke Calibration 2638A also provides frequency measurement capability.

This expands the range of possible applications beyond conventional temperature and electrical data logging.

Frequency signals from suitable sensors, generators and industrial devices can be included in automated measurement sequences.

This flexibility makes the instrument useful for complex test systems where several different electrical quantities must be monitored simultaneously.

Modular Input Architecture

The Fluke Calibration 2638A uses removable input modules.

This allows sensors to be connected conveniently outside the instrument before the module is inserted into the mainframe.

A modular system provides several advantages.

Frequently used sensor configurations can remain wired to a module.

This reduces setup time when repeated tests are performed.

Different modules can also be prepared for different measurement applications.

The instrument can therefore be adapted quickly to changing laboratory or production requirements.

Large Color Graphical Display

The Fluke Calibration 2638A features a large color display designed to provide clear visualization of measurement results.

Users can view numerical measurement values as well as graphical trends.

Real-time trend displays make it easier to identify:

• Temperature changes
• Measurement drift
• Stabilization behavior
• Unexpected signal variations
• Limit violations

Graphical visualization is particularly useful during environmental chamber testing and temperature mapping.

The user can observe the measurement process directly without continuously monitoring the system from an external computer.

Integrated Data Logging

The Fluke Calibration 2638A provides integrated data logging functionality.

Measurement results can be stored automatically together with time and channel information.

This allows long-term measurements to be performed without continuous operator intervention.

Typical data logging applications include:

• Temperature monitoring
• Environmental chamber qualification
• Process monitoring
• Product testing
• Stability measurements
• Research experiments
• Production testing
• Quality assurance

Measurement data can subsequently be transferred to a computer for analysis, documentation or archiving.

USB Storage

The Fluke Calibration 2638A supports USB memory devices.

Measurement data and configuration files can therefore be transferred conveniently between the instrument and a computer.

USB storage also simplifies measurement workflows where the instrument operates independently from a permanently connected PC.

Test configurations can be prepared, stored and reused for repeated measurement procedures.

LAN and USB Communication

For automated measurement systems, the Fluke Calibration 2638A provides modern communication interfaces.

The instrument supports:

• LAN
• USB

These interfaces allow the system to be controlled from a computer and integrated into automated test environments.

Remote operation is particularly useful for long-term monitoring and production test applications.

Measurement data can be collected automatically and processed by external software.

Mathematical Functions

The Fluke Calibration 2638A provides mathematical functionality for processing measured values.

Calculated channels can be used to derive additional information directly from the measured data.

Typical applications include:

• Temperature differences
• Sensor comparison
• Scaling of transmitter signals
• Conversion of electrical signals
• Statistical evaluation

For example, the difference between two temperature sensors can be calculated to monitor temperature uniformity.

This reduces the need for manual calculations after the measurement.

Alarm Functions

The Fluke Calibration 2638A provides configurable alarm functions.

Upper and lower limits can be defined for measurement channels.

If a measured value exceeds a specified limit, the system can identify the corresponding condition.

Alarm outputs can be used for integration into suitable external systems.

This functionality is particularly useful for environmental monitoring, industrial processes and automated test applications.

Temperature Mapping

One of the major applications of the Fluke Calibration 2638A is temperature mapping.

Temperature mapping determines the spatial temperature distribution within a controlled environment.

Typical examples include:

• Climate chambers
• Temperature chambers
• Refrigerators
• Freezers
• Ovens
• Furnaces
• Storage rooms
• Pharmaceutical warehouses

Multiple temperature sensors can be distributed throughout the test volume and connected to the 2638A.

The instrument then records all measurement points according to the selected scanning interval.

The resulting data can be used to evaluate temperature uniformity, stability and gradients.

Environmental Chamber Testing

The high channel capacity of the Fluke Calibration 2638A makes it particularly suitable for environmental chamber testing.

Multiple temperature sensors can be combined with electrical measurement channels.

This allows environmental conditions and the electrical behavior of a device under test to be recorded simultaneously.

For example, temperature, voltage and current can be monitored during a thermal cycling test.

This capability makes the instrument useful in research, development and product qualification.

Industrial Process Monitoring

The Fluke Calibration 2638A can also be integrated into industrial process monitoring applications.

Temperature sensors, transmitters and electrical signals can be monitored within the same system.

This makes it possible to evaluate the relationship between process temperature and electrical process variables.

Integrated data logging allows measurement values to be recorded over extended periods for later evaluation.

Fluke Calibration 2638A or 1586A?

The Fluke Calibration 2638A and Fluke Calibration 1586A are both multi-channel measurement systems, but they are optimized for different applications.

The Fluke Calibration 2638A Hydra Series III is a highly flexible general-purpose data acquisition system.

It provides up to 66 differential or 120 single-ended channels and supports temperature as well as numerous electrical measurement functions.

The Fluke Calibration 1586A Super-DAQ is optimized more specifically for precision temperature measurement and automated temperature sensor calibration.

The 1586A provides up to 40 isolated universal input channels and offers higher precision for demanding temperature metrology applications.

Choose the 2638A when high channel density and broad data acquisition capability are the primary requirements.

Choose the 1586A when precision temperature measurement and temperature calibration are the main priorities.

Technical Highlights

Calibration Service by europascal

Reliable data acquisition depends on the metrological performance of the complete measurement chain.

europascal provides professional calibration services for temperature and electrical measuring equipment.

When the Fluke Calibration 2638A is used for temperature measurements, relevant uncertainty contributions can include the accuracy of the data acquisition system, sensor calibration uncertainty, connection technique, reference junction compensation, resolution and measurement repeatability.

For temperature mapping applications, additional influences such as sensor positioning, temperature stability and spatial temperature uniformity should be considered.

Electrical measurement applications require the relevant voltage, current, resistance or frequency measurement specifications to be considered according to the selected range and configuration.

For professional calibration services and metrological traceability, visit the europascal Calibration Service.

Why Choose the Fluke Calibration 2638A?

The Fluke Calibration 2638A Hydra Series III combines high channel density, flexible sensor support and comprehensive data acquisition functionality in one professional measurement system.

Up to 66 differential or 120 single-ended channels make the instrument suitable for large measurement setups.

Scan rates of up to 46 channels per second allow large numbers of measurement points to be acquired efficiently.

Support for thermocouples, RTDs, thermistors, DC voltage, AC voltage, DC current, resistance and frequency allows different sensor technologies and electrical signals to be combined within a single measurement system.

The modular input architecture simplifies sensor wiring and allows frequently used configurations to be prepared in advance.

Integrated data logging and graphical trending provide convenient standalone operation, while USB and LAN interfaces enable integration into automated measurement systems.

For calibration laboratories, industrial quality assurance, environmental chamber testing, research and production applications requiring flexible multi-channel measurements, the Fluke Calibration 2638A provides a powerful and versatile solution.

europascal supports customers with professional measurement equipment, technical advice and calibration services.

Typical Applications for the Fluke Calibration 2638A

Typical applications include:

• Multi-channel temperature measurement
• Temperature mapping
• Environmental chamber qualification
• Climate chamber monitoring
• Oven and furnace mapping
• Refrigerator and freezer mapping
• Thermocouple measurements
• RTD measurements
• Thermistor measurements
• Process monitoring
• Electrical data acquisition
• Product testing
• Thermal cycling tests
• Research and development
• Production testing
• Quality assurance
• Calibration laboratories
• Long-term data logging

The combination of high channel density, fast scanning, broad sensor compatibility and flexible data logging makes the Fluke Calibration 2638A Hydra Series III a professional solution for demanding multi-channel measurement applications.

Find more Fluke Calibration products here.

Manufacturer information for the Fluke Calibration 2638A can be found on the official Fluke Calibration website.

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