What types of humidity chambers does ESPEC offer?

ESPEC provides a diverse range of humidity test chambers to meet various testing needs, including:

• Benchtop Models: Compact and versatile, ideal for small-scale testing.
• Platinous Chambers: Our flagship product for general temperature and humidity control.
• Global-N Temperature Cycling Chambers: temperature cycling and humidity for speed or large loads.
• Walk-in Chambers: Spacious chambers for bulk or large product testing requirements.

Each type is tailored to specific humidity and temperature testing conditions, ensuring optimal performance for your application.

What is the temperature and humidity range of an ESPEC humidity test chamber?

ESPEC’s humidity chambers can accommodate a broad spectrum of conditions:

• Temperature Range: From -70°C to 180°C.
• Humidity Range: From 10% to 95% RH, with special options available for ultra-low humidity operations down to 5% RH.

These ranges allow for rigorous environmental testing, making them suitable for various industries and applications.

Can I customize the humidity chambers with additional features?

Yes, an ESPEC humidity test chamber can be customized to fit your specific needs. Options include:

• Additional shelves
• Data acquisition systems
• Special controllers
• Water supply tanks with recirculation mode
• Humidity sensor types (wet-bulb or solid state)
• Leak pans and alarms

Customizing your humidity test chamber ensures it meets your precise testing requirements and operational needs.

What are the differences between Panelized and Solid Walk-in Chambers?

• Panelized Walk-in Chambers: Constructed with insulated panels, these chambers are designed for humidity testing up to 75°C and 95% RH.
• Solid Walk-in Chambers: Featuring a one-piece welded construction, these chambers offer enhanced durability and are suited for extreme conditions, including 85°C/85% RH.

The choice between these models depends on the specific conditions and durability required for your testing.

How do I choose the right humidity chamber for my needs?

Selecting the appropriate chamber depends on your testing requirements:

• Benchtop and Platinous Reach-in Chambers: Suitable for most humidity tests with a smaller refrigeration system.
• Global-N Series: Ideal for temperature cycling and advanced performance testing.

Consulting with an ESPEC representative can help you determine the best model based on your specific needs, whether for routine humidity tests or more complex environmental conditions.

What are the typical lead times for ESPEC temperature humidity chambers?

• Benchtop and Platinous Standard Models: Often available for quick shipment, noted as “Quick Ship” on our website.
• Performance and Built-to-Order Chambers: Lead times vary; please request a quote from ESPEC for details based on your specific requirements.

We strive to provide timely solutions to meet your testing needs efficiently.

Can I use ESPEC humidity testing chambers for continuous testing?

Yes, ESPEC humidity chambers are designed for continuous and reliable operation, making them suitable for long-term testing scenarios such as durability and lifespan studies under controlled humidity conditions.

What maintenance is required for ESPEC humidity testing chambers?

Regular maintenance includes:

• Checking and replacing water filters
• Ensuring proper operation of humidification systems
• General cleaning

ESPEC provides maintenance guides and support to help keep your chamber in optimal condition.

Are there specific humidity control systems used in ESPEC chambers?

ESPEC humidity chambers utilize advanced humidity control systems, including:

• Vapor Generator
• Water-Bath Humidification Methods

Each model series is equipped with a system tailored to its ideal operation, ensuring stable and precise humidity conditions.

Why Humidity Testing Chambers?

Humidity testing chambers play a crucial role in:

• Reliable and Accurate Testing Results: Ensures your products perform as expected under varied environmental conditions.
• Simulation of Real-World Conditions: Mimics real-life scenarios such as high humidity and temperature cycling.
• Stress and Accelerated Testing: Tests products under extreme conditions to predict long-term performance.
• Freeze/Thaw and Condensation Simulation: Alternates between high humidity and cold/freezing temperatures to simulate environmental stress.

Common Applications

• Stable Control: Maintains consistent temperature and humidity levels for accurate testing.
• Durable Construction: Designed for reliable, long-term use.
• Advanced Technology: Features like programmable touch-screen controllers and USB/Ethernet connectivity.

Customization and Optional Features

ESPEC chambers can be tailored with various options:

• Water Filtering
• Water Supply Tanks (with recirculation mode)
• Humidity Sensor Types (wet-bulb or solid state)
• Leak Pans and Alarms

Support and Services

• Water Supply: Chambers need a water source; a filter is required if using city water, or a local water supply tank can be purchased if no water source is available.
• Drainage: Chambers require a gravity drain to remove spent water. The drain must be near and lower than the chamber.
• Free “Remote Start-Up” Service: Get quick and efficient setup assistance for your humidity operation.

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Feel free to contact us for more information or assistance with your humidity testing needs.

There are two different systems for measuring humidity in environmental test chambers. One is analog, the other digital. But which is really better? Lets look at the pluses and minuses of each.

Analog method: wet bulb/dry bulb

A dry bulb is simply a dry thermocouple in the air (the word bulb refers to a thermometer bulb). A wet bulb is a thermocouple with a fabric “sock” or “wick” that is kept wet by hanging the end in a small tank of water. When the wet and dry bulbs are placed in the air-stream of the chamber, the wet bulb is colder because the water on it is constantly evaporating. The chamber controller compares the temperatures of the two thermocouples and calculates the relative humidity. It is a fundamental measurement method because it is a direct application of thermodynamic principles.

Wet-bulb Pluses:

• Reliable, simple technology
• Easy to maintain
• No calibration required
• Easy to determine if malfunctioning (starts reading 100%)
• Only two typical failure modes: wick needs changing or water supply is gone
• Wicks are cheap to replace

Wet-bulb Minuses:

• Need to change wick regularly
• Not suitable for temperatures below 3°C or above 95°C

Digital method: solid-state sensor

As the name implies, the solid-state sensor is electronic. The sensor measures the electrical capacitance of a special material as it changes with the humidity. It has its own processor to interpret the capacitance change and then outputs a humidity value to the chamber controller. It is considered a secondary measurement method because it is based on the observed properties of the sensor material.

Solid-state Pluses:

• No wick to change
• Can read humidity below freezing and above boiling (although normal chambers can’t control at these conditions)

Solid-state Minuses:

• Malfunction (loss of calibration) cannot be detected easily
• Can be damaged by extreme temperatures
• Can be damaged (temporary or permanent) by condensation (when operated near 100% RH)
• Needs regular calibration (every 6 months)
• Requires specialized equipment for proper calibration and adjustment
• Accuracy varies depending on temperature
• Expensive to replace

Which to choose?

For the end-user, one of the primary interests is maintenance. Oftentimes a solid-state system sounds easier because you don’t have to worry about changing the wick. But instead you are adding an additional device that needs to be calibrated and maintained. Today, most chamber companies use solid-state sensors as standard, primarily because they are simpler to install and allow use of less-sophisticated controllers.

ESPEC uses wet/dry bulb on our standard chambers because it is more reliable and easy to maintain. ESPEC does offer solid-state systems where extreme conditions need to be measured, or if the wick location would be hard to get to.

We have perfected our wet-bulb system. We have wicks made especially for use with our chambers to provide long service and even ‘wetting’ because they are wide and flat. And we use only the most accurate humidity calculation method, not commonly available on other chamber controllers.

There are three common ways of creating moisture for humidity control in test chambers. Let’s review they types and the benefits and limitations of each.

Type 1: “Steam Generator”

A steam generator is a tank with an immersion heater. As the water in the tank is heated, steam rises up a tube to the chamber’s mixing plenum (where the main heaters and cooling coil are). The chamber, based on humidity demand, controls the output of the heater.

Benefits:

• High volume of moisture can be generated (good for large chambers)
• Quality of water vapor is consistent

Limitations:

• Large amount of water to heat delays initial steam supply
• Needs to be nearly boiling to generate steam for even moderate humidity levels
• Constant boiling leaves excessive deposits of minerals
• Must disassemble for inspection/cleaning
• Larger heater required for generating steam

Type 2: “Atomizer”

Atomizers use a fine-spray nozzle to “atomize” the water. This is done in the mixing plenum. As the atomized water passes the chamber heater, it becomes heated to a gas.

Benefits:

• Very simple system
• Can provide high volume of moisture
• No problems with heater burn-out
• Said to save electricity because water isn’t directly heated
• Cools the air (beneficial when needed)

Limitations

• Potential for clogging of spray nozzle
• Water droplets must be fully heated to vaporize
• Dependant on water quality supplied
• Difficult to produce high-humidity at higher temperatures
• Minerals in the water result in fine dust throughout the chamber

Type 3: “Water bath”

Like a steam generator, but not in an enclosed box. A small “bath” is located in the mixing plenum. As the chamber air is drawn into the plenum, it passes the bath, picking up vapor.

Benefits:

• Quick response due to small water amount
• Doesn’t have to be at boiling to provide moisture
• Less boiling means less mineral deposits to clean
• Can be inspected and cleaned quickly

Limitations:

• Can’t generate high-volumes of moisture
• Constant presence of water in bath during humidity tests can make low-humidity control difficult.

Now, you are wondering, which does ESPEC use? All three, depending on the application. For our standard chambers, we use the water bath system. For larger systems, we use the steam generator. And for certain low-temperature, high-humidity applications, we use the atomizer.