GEO Calibration Model 4000 EXP is a versatile humidity calibrator and temperature generator designed for professional calibration of larger humidity measuring instruments, data loggers, chart recorders and probes. Its vertical design, large 30-liter square calibration chamber and temperature-controlled door make the system particularly suitable for demanding laboratory applications and calibration equipment that cannot easily be accommodated in conventional compact humidity generators.

The Model 4000 EXP generates controlled relative humidity and temperature conditions for professional comparison calibration. At 23 °C, the system provides a controlled relative humidity range from 10 % RH to 90 % RH. The temperature can be controlled within approximately ±5 °C of ambient temperature.

The specified calibration system accuracy is ±3.0 % RH or better for relative humidity and ±0.3 °C or better for temperature.

A key feature of the GEO Calibration Model 4000 EXP is its temperature-controlled door. It is designed to reduce the influence of changes in external ambient temperature on the conditions inside the calibration chamber.

Combined with automatic Ramp/Soak functionality and a typical response time of approximately 3 to 5 minutes, the Model 4000 EXP provides a practical solution for repeatable multipoint humidity calibration.

At europascal, you receive professional solutions for humidity and temperature calibration. We can assist you in selecting the appropriate humidity generator, reference sensor and accessories for your calibration application.

For regular calibration and metrological traceability of humidity and temperature measuring instruments, europascal also provides a professional Calibration Service.

Your Benefits at a Glance

• Versatile humidity and temperature calibrator
• Vertical calibration chamber
• Large 30-liter square chamber
• Relative humidity range from 10 % RH to 90 % RH at 23 °C
• Temperature range approximately ±5 °C from ambient
• Relative humidity accuracy ±3.0 % RH or better
• Temperature accuracy ±0.3 °C or better
• PID-controlled humidity and temperature generation
• Temperature-controlled chamber door
• Temperature uniformity 0.3 °C at 23 °C
• Humidity uniformity 3.0 % RH at 23 °C
• Temperature stability 0.2 °C
• Humidity stability 1 % RH at 23 °C
• Temperature resolution 0.1 °C
• Humidity resolution 0.1 % RH
• Automatic Ramp/Soak functionality
• Typical response time approximately 3 to 5 minutes
• Suitable for data logger calibration
• Suitable for chart recorder calibration
• Suitable for humidity probe calibration
• Designed to accommodate legacy hair hygrometers
• Particularly suitable for vertical calibration systems
• Designed for demanding environments
• Professional solution for calibration laboratories

GEO Calibration Model 4000 EXP for Professional Humidity Calibration

The GEO Calibration Model 4000 EXP was developed for applications where conventional compact humidity calibrators do not provide sufficient chamber volume or the appropriate physical configuration.

Its vertical design and large calibration chamber enable users to accommodate a variety of devices under test.

Typical applications include:

• Calibration laboratories
• In-house calibration laboratories
• Quality assurance
• Measuring equipment monitoring
• Environmental monitoring
• Pharmaceutical applications
• Food production and storage
• HVAC measurement
• Building automation
• Research and development
• Industrial process measurement
• Production monitoring
• Data logger calibration
• Chart recorder calibration
• Humidity probe calibration

The Model 4000 EXP is particularly useful for devices that require a larger chamber or need to be positioned vertically during calibration.

Large 30-Liter Calibration Chamber

One of the main advantages of the GEO Calibration Model 4000 EXP is its large calibration chamber.

The square chamber provides a volume of approximately:

30 liters

This provides considerably more space than compact portable humidity generators.

The additional chamber volume is particularly useful when calibrating larger devices or several suitable measuring instruments.

Typical devices under test include:

• Data loggers
• Chart recorders
• Humidity probes
• Temperature and humidity sensors
• Hygrometers
• Environmental monitoring instruments
• Legacy hair hygrometers

The square geometry also simplifies positioning of instruments that do not fit conveniently into smaller cylindrical calibration chambers.

Relative Humidity from 10 % to 90 % RH

At an operating temperature of 23 °C, the GEO Calibration Model 4000 EXP provides a controlled humidity range from:

10 % RH to 90 % RH

This covers a large proportion of typical humidity calibration requirements.

The available humidity range changes with temperature.

Typical specified ranges include:

At 18 °C: 10 % to 70 % RH

At 23 °C: 10 % to 90 % RH

At 28 °C: 10 % to 70 % RH

This relationship is important when planning calibration points because the achievable relative humidity depends on the selected chamber temperature.

Temperature Control Around Ambient Conditions

The GEO Calibration Model 4000 EXP also provides active temperature control.

Its controlled temperature range is approximately:

Ambient temperature ±5 °C

This makes the Model 4000 EXP particularly suitable for humidity calibrations performed around typical laboratory or operating temperatures.

Temperature control is especially important in relative humidity calibration because relative humidity is highly dependent on temperature.

Even relatively small temperature differences between the reference sensor and device under test can influence the measurement result.

The controlled chamber therefore provides a more suitable environment for professional comparison calibration than uncontrolled ambient conditions.

Humidity Accuracy of ±3.0 % RH

The specified relative humidity calibration system accuracy is:

±3.0 % RH or better

This makes the GEO Calibration Model 4000 EXP suitable for numerous industrial humidity calibration and verification applications.

When determining the measurement uncertainty of an actual calibration, however, the generator specification is only one contribution.

The complete uncertainty evaluation may also include:

• Reference sensor calibration uncertainty
• Humidity stability
• Spatial humidity uniformity
• Temperature stability
• Temperature gradients
• Resolution
• Repeatability
• Device under test characteristics
• Sensor positioning
• Stabilization effects

These contributions should be evaluated according to the laboratory’s calibration procedure and required measurement uncertainty.

Temperature Accuracy of ±0.3 °C

The specified temperature calibration system accuracy is:

±0.3 °C or better

Temperature and humidity are controlled simultaneously by the system.

This is particularly useful when calibrating combined temperature and humidity instruments such as environmental data loggers.

Instead of evaluating humidity under uncontrolled temperature conditions, the Model 4000 EXP provides a defined calibration environment for both quantities.

Temperature-Controlled Door

A distinctive feature of the GEO Calibration Model 4000 EXP is its temperature-controlled door.

Large calibration chambers can be sensitive to external environmental influences, particularly around access points and chamber doors.

The temperature-controlled door is designed to help maintain the internal temperature and reduce the influence of changes in ambient conditions.

This feature is particularly useful when large devices under test are positioned inside the chamber and stable conditions need to be maintained throughout the calibration process.

PID-Controlled Calibration Environment

The GEO Calibration Model 4000 EXP uses PID control for humidity and temperature generation.

The controller continuously evaluates the actual chamber conditions and adjusts the system to maintain the selected setpoints.

The specified temperature uniformity is:

0.3 °C at 23 °C

The specified relative humidity uniformity is:

3.0 % RH at 23 °C

Temperature stability is specified as:

0.2 °C

Relative humidity stability is specified as:

1 % RH at 23 °C

These characteristics are important when reference sensors and devices under test are compared within the calibration chamber.

Automatic Ramp/Soak Function

The GEO Calibration Model 4000 EXP supports automatic Ramp/Soak operation.

Ramp/Soak functionality enables controlled transitions between different temperature and humidity setpoints and allows defined conditions to be maintained for a specified period.

This can be particularly useful for multipoint calibration.

Instead of manually changing each calibration condition, a sequence can be created to move through several measurement points.

This supports more efficient and reproducible calibration workflows.

Typical Ramp Rates

The Model 4000 EXP is designed for controlled transitions between calibration conditions.

Typical rates are approximately:

Temperature, low to high: 1 °C/min

Humidity, low to high: 1 % RH/min

Humidity, high to low: approximately 1 % RH/min

The actual time required to reach a stable calibration condition depends on the selected setpoints, ambient conditions, chamber loading and response characteristics of the devices under test.

Fast Response

The GEO Calibration Model 4000 EXP is specified with typical response times of approximately:

3 to 5 minutes

Fast system response can reduce waiting periods when several calibration points need to be processed.

However, the response time of the generator should not be confused with the stabilization time required for the complete calibration.

A large data logger, chart recorder or humidity probe may require additional time to reach thermal and humidity equilibrium with the chamber.

Measurement values should therefore only be recorded after both the reference and device under test have sufficiently stabilized.

Data Logger Calibration

The large chamber makes the GEO Calibration Model 4000 EXP particularly suitable for calibration of environmental data loggers.

Data loggers are frequently used to monitor temperature and humidity in:

• Warehouses
• Pharmaceutical storage
• Laboratories
• Production areas
• Cleanrooms
• Transport systems
• Museums
• Archives
• Food storage facilities

Several suitable data loggers can be exposed to the same controlled environment.

This makes the Model 4000 EXP particularly useful for organizations that need to regularly verify environmental monitoring equipment.

Chart Recorder Calibration

The 30-liter chamber also provides sufficient space for many chart recorders.

Chart recorders continue to be used in applications where a direct graphical record of environmental conditions is required.

The Model 4000 EXP allows suitable chart recorders to be exposed to defined humidity and temperature conditions.

Their indications can then be compared with a calibrated reference system.

Support for Legacy Hair Hygrometers

The GEO Calibration Model 4000 EXP was also engineered to support legacy hair hygrometers.

These instruments use the dimensional change of hygroscopic material as the sensing principle for relative humidity.

Their mechanical construction can make calibration in compact chambers difficult.

The larger vertical chamber of the Model 4000 EXP provides a more suitable environment for these types of instruments.

This makes the calibrator useful for laboratories that need to maintain and calibrate both modern electronic humidity sensors and older mechanical hygrometers.

Ideal for Vertical Calibration Systems

The vertical construction of the GEO Calibration Model 4000 EXP distinguishes it from many conventional benchtop humidity generators.

Some instruments and sensors need to remain in a particular orientation during measurement or calibration.

The vertical chamber configuration provides additional flexibility for these applications.

GEO Calibration specifically identifies calibration of vertical systems as one of the intended applications for the Model 4000 EXP.

Comparison Calibration

A typical calibration with the GEO Calibration Model 4000 EXP is performed using the comparison method.

A calibrated reference humidity sensor and the device under test are placed inside the controlled chamber.

A defined relative humidity and temperature setpoint is selected.

After sufficient stabilization, the reference value and indication of the device under test are recorded.

The deviation can then be calculated.

This procedure can be repeated at several humidity points, for example:

• Low relative humidity
• Medium relative humidity
• High relative humidity

The exact calibration points should be selected according to the measurement range, application and required calibration procedure.

Technical Highlights

The GEO Calibration Model 4000 EXP combines a large calibration volume with controlled humidity and temperature generation:

• 30-liter square calibration chamber
• Vertical chamber design
• Relative humidity range 10 % to 90 % RH at 23 °C
• Temperature range ambient ±5 °C
• Humidity accuracy ±3.0 % RH or better
• Temperature accuracy ±0.3 °C or better
• PID controller
• Temperature uniformity 0.3 °C at 23 °C
• Humidity uniformity 3.0 % RH at 23 °C
• Temperature stability 0.2 °C
• Humidity stability 1 % RH at 23 °C
• Temperature resolution 0.1 °C
• Humidity resolution 0.1 % RH
• Automatic Ramp/Soak
• Typical response time 3 to 5 minutes
• Temperature-controlled door
• Suitable for large calibration equipment
• Data logger calibration
• Chart recorder calibration
• Probe calibration
• Legacy hair hygrometer support

Technical Specifications

GEO Calibration Model 4000 EXP for Demanding Environments

The GEO Calibration Model 4000 EXP is designed not only for conventional laboratory environments but also for demanding applications.

Its temperature-controlled door helps reduce the influence of changes in external ambient temperature on the chamber conditions.

This is particularly useful where environmental conditions are less stable than in a dedicated high-quality calibration laboratory.

For reliable measurements, the installation environment should nevertheless always comply with the manufacturer’s operating requirements.

Why Choose the GEO Calibration Model 4000 EXP?

The GEO Calibration Model 4000 EXP provides a combination of large calibration volume, vertical construction and controlled temperature and humidity generation.

Its 30-liter square chamber accommodates larger devices that cannot easily be calibrated in compact humidity generators.

A relative humidity range from 10 % RH to 90 % RH at 23 °C covers a broad spectrum of typical industrial humidity calibration applications.

The temperature-controlled door helps maintain consistent chamber conditions, while automatic Ramp/Soak functionality supports repeatable multipoint calibration sequences.

The Model 4000 EXP is particularly suitable for calibration of data loggers, chart recorders, humidity probes and legacy hair hygrometers.

For calibration laboratories, quality assurance departments and organizations with larger environmental monitoring instruments, the system therefore provides a versatile solution for professional humidity calibration.

At europascal, we can assist you in selecting the appropriate GEO Calibration humidity generator, reference sensor and accessories for your individual application.

For regular calibration and metrological traceability of humidity sensors, data loggers, hygrometers and other measuring instruments, use the europascal Calibration Service.

Additional measurement and calibration solutions are available through the europascal English homepage.

Discover more GEO Calibration products and calibration solutions from europascal.

Manufacturer information about the GEO Calibration Model 4000 EXP is available from the official GEO Calibration website.

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