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LAB EQUIPMENT REPAIRS, INCLUDING ULTRALOW FREEZERS, FRIDGES, CENTRIFUGES AND MORE - Click here for details
LAB EQUIPMENT REPAIRS, INCLUDING ULTRALOW FREEZERS, FRIDGES, CENTRIFUGES AND MORE - Click here for details

Thermo Forma 3940 Refrigerated Environmental Chamber

Fully Tested & Warrantied*
Brand : Thermo
Product Code : SKU 3175GG INC

Shipping

All products ship from our 30,000 sq. ft. Haverhill, MA warehouse

Thermo Forma 3940 Refrigerated Environmental Chamber

The Thermo Forma 3940 Refrigerated Environmental Chamber is a high-performance stability and environmental testing chamber engineered for precise temperature and humidity control in pharmaceutical, biotechnology, clinical, and research laboratory applications. Designed for both above-ambient and sub-ambient operation, the Thermo 3940 delivers exceptional environmental uniformity and reliability for demanding stability studies, shelf-life testing, incubation, and environmental simulation applications.

Thermo Forma 3940 features

    Thermo Forma 3940 features

    • Temperature range: 0°C to 60°C with precise 0.1°C resolution for environmental testing and incubation applications
    • Humidity range: ambient to 95% RH with 1% readability for controlled stability studies
    • Large 29 cu. ft. chamber capacity for high-volume testing and incubation workflows
    • Directed airflow system provides exceptional temperature uniformity across all shelves
    • Excellent temperature uniformity of ±0.3°C at 25°C to 37°C for consistent testing conditions
    • Rapid temperature recovery after door openings helps maintain stable environmental conditions
    • Designed for ICH-compliant pharmaceutical stability and shelf-life testing applications
    • Solid insulated door improves environmental stability and energy efficiency
    • Microprocessor controls enable precise programmable temperature and humidity management
    • 90 day warranty from American Instrument Exchange

    Professionally refurbished by American Instrument Exchange each Thermo Forma 3940 Refrigerated Environmental Chamber undergoes comprehensive testing and validation to verify temperature accuracy, humidity performance, airflow uniformity, refrigeration operation, and control system functionality—providing dependable laboratory performance at substantial savings compared to new environmental chambers.

    Featuring a large-capacity reach-in chamber design and Thermo Scientific’s advanced directed airflow system, the Thermo 3940 maintains highly stable environmental conditions even under heavy sample loads or frequent door openings. Unlike conventional top-down airflow chambers, the directed airflow system uses positive and negative pressure plenums to distribute conditioned air evenly throughout the chamber for superior temperature consistency and recovery performance.

    The Thermo Forma 3940 is widely used for pharmaceutical stability testing, drug storage studies, packaging validation, biological incubation, microbiology research, agricultural studies, insect research, and environmental simulation testing. Its combination of precise humidity control, broad temperature range, and large chamber volume make it a versatile solution for laboratories requiring tightly controlled environmental conditions.

    Thermo Forma 3940 - additional features

    Temperature uniformity and recovery can deteriorate quickly when shelves are filled because air movement is blocked. That variation in temperature, alone or when combined with frequent door openings, may compromise environmental conditions, or make process validation difficult. 

    The Thermo Scientific Directed Airflow System promotes an ideal growth environment. The enhanced design includes a positive pressure feed plenum on the right side of the chamber and a negative pressure return plenum on the left to distribute the airflow uniformly throughout the chamber.

    Thermo 3940 incubator technical specifications

    • Model: 3940
    • Chamber Volume: 29 cu. ft.
    • Temperature Range: 0°C to 60°C
    • Temperature Accuracy: ±0.1°C at 25°C to 37°C
    • Temperature Uniformity: ±0.3°C at 25°C to 37°C
    • Temperature Resolution: 0.1°C
    • Humidity Range: Ambient to 95% RH
    • Humidity Accuracy: ±5% RH
    • Humidity Readability: 1%
    • External Dimensions: 38"W × 32"D × 88.5"H
    • Internal Dimensions: 31"W × 27"D × 60"H
    • Electrical Requirements: 208/220V, 60Hz
    • Door Type: Solid insulated door
    • Airflow System: Directed airflow plenum system
    • Cooling System: Refrigerated environmental chamber system

    Thermo Forma 3940 Refrigerated Environmental Chamber Testing

    Most of our equipment is used and reconditioned. All of our incubators are used and reconditioned. We test incubators using a calibrated digital chart recorder to verify the accuracy of temperature controls and readouts. We replace any hardware or parts as is necessary and clean all incubators thoroughly prior to shipment.  

    Thermo Forma 3940 Pictures

    The photos above are representative. Please bear in mind that the equipment shown is currently in storage in our warehouse. In addition to testing each machine we will clean all the equipment thoroughly prior to shipment.

    We often have multiple units of each model in stock. Sometimes we're unable to feature photos of every single unit. At your request, we can provide photos of the equipment in your order after testing and cleaning. 

    For inquiries about the Thermo Forma 3940 Refrigerated Environmental Chamber, please give us a call at 978-521-2221, or fill out the form on this page.

    Thermo Forma 3940 Incubator – Frequently Asked Questions

    What applications is the Thermo 3940 environmental chamber used for?

    The Thermo Forma 3940 is designed for precise control of temperature and humidity in both above-ambient and sub-ambient conditions. In other words, this model can both heat and cool, and provide stable humidity, making it a versatile option for a wide range of uses.

    The 3940 is commonly used for pharmaceutical stability testing (ICH-compliant), shelf-life studies and packaging validation, microbiology and biological incubation, environmental and insect research, and any other application requiring a large chamber with tightly controlled temperature and humidity.

    Labs searching for used environmental chambers often choose the 3940 due to its reliability, large capacity, and regulatory compatibility.

    Explore more options: Browse our full selection of used environmental chambers to compare available inventory.

    What makes the Thermo 3940 different from other used environmental chambers?

    A key advantage of the Thermo Forma 3940 environmental chamber is its directed airflow system. This provides uniform air distribution across all shelves without large variance in temperature throughout the chamber. In other words, the airflow creates temperature uniformity throughout the chamber. It also improves faster recovery after door openings and stable performance under heavy loads.

    Compared to many used environmental chambers that rely on top-down airflow, the 3940 offers superior uniformity, which is critical for stability testing and GMP environments.

    Is the Thermo 3940 suitable for pharmaceutical stability testing?

    Yes. The Thermo 3940 environmental chamber is commonly used in:

    • GMP and GLP laboratories
    • ICH stability protocols
    • FDA-regulated environments

    Its precise control and programmability make it a top choice among buyers searching for used environmental chambers for stability testing.

    What features of the Thermo 3940 support controlled environments and compliance?

    Key features include:

    • Microprocessor-based control system
    • Programmable ramp/soak profiles
    • High/low temperature safety alarms
    • Humidity control via steam generator
    • Remote monitoring outputs

    These features help labs maintain validated, auditable environmental conditions, especially important when purchasing used environmental chambers for regulated or other highly sensitive workflows.

    How does the Thermo 3940 compare to similar models?

    Thermo Forma 3940 vs 3920

    • Similar capacity and temperature range
    • 3940 often includes more advanced programmability
    • 3940 features humidity; standard 3920 does not
    • Both are common in the used environmental chamber market

    Thermo 3940 vs Percival Chambers

    • 3940: Better for pharma stability and uniformity
    • Percival: Better for plant growth and lighting applications

    Thermo 3940 vs Binder Chambers

    • Thermo: Strong airflow and durability
    • Binder: Often newer interface, but higher cost

    Why buy a used and refurbished Thermo 3940 environmental chamber?

    Buying a used environmental chamber like the Thermo 3940 offers:

    • Significant cost savings vs. new
    • Proven long-term reliability
    • Availability of replacement parts and service
    • Immediate availability (no long lead times)

    This model remains one of the most sought-after used environmental chambers due to its performance and durability.

     

    Testing Procedures for Used and Refurbished Laboratory Equipment

    Ensure Accuracy, Safety, and Dependable Performance Across Applications

    At American Instrument Exchange, all used and refurbished laboratory equipment undergoes a rigorous, multi-point testing protocol to ensure optimal performance, operational safety, and long-term reliability. Whether the equipment is destined for research, diagnostics, quality control, or production environments, our thorough inspection and testing process is designed to meet the highest standards of laboratory excellence.

    Why Testing Used Lab Equipment Is Essential

    Before any refurbished laboratory equipment is returned to service, it must be carefully tested to verify:

    • Functional integrity and operational performance
    • Setpoint accuracy and repeatability (where applicable)
    • User interface responsiveness and control features

    Proper testing reduces the risk of equipment failure, measurement inaccuracies, or user hazards—helping to ensure consistent results in clinical, academic, biotech, and industrial labs.

    Our standardized lab equipment testing procedures are tailored to each equipment type, ensuring every unit meets manufacturer specifications and industry benchmarks.

    Key Testing Procedures for Refurbished and Used Laboratory Equipment

    1. Initial Visual Inspection

    • Examine equipment housing for signs of wear, corrosion, or damage
    • Check ports, power cords, and exterior components for tampering or deterioration
    • Verify that internal and external parts (racks, shelves, connectors, accessories) are present and undamaged

    2. Functional Startup and Operational Testing

    • Power on the equipment and verify startup diagnostics
    • Confirm functionality of displays, buttons, switches, and control panels
    • Run basic functions to confirm proper response and behavior under standard operating conditions

    3. Testing and Performance Verification

    • Test internal sensors or control systems using industry-standard tools
    • Perform operational tests to validate accuracy and consistency
    • Verify key performance specifications such as temperature control, timing, speed, or measurement outputs, depending on equipment type

    4. Mechanical and Electrical System Testing

    • Evaluate motors, pumps, fans, or other moving parts for smooth operation
    • Inspect and test wiring, relays, fuses, and circuit boards for safety and reliability
    • Test power delivery and grounding compliance

    5. Safety and Compliance Checks

    • Ensure equipment is grounded and insulated to meet laboratory safety standards
    • Test alarms, interlocks, emergency stops, or safety shutdown systems if applicable

    6. Final Quality Assurance and Documentation

    • Perform extended runtime testing
    • Document operational logs, testing results, and any repairs or adjustments made
    • Complete a final inspection, thorough cleaning, and packaging for delivery

    Trusted Quality from American Instrument Exchange

    With over 50 years of experience in laboratory equipment refurbishment, American Instrument Exchange is committed to delivering certified, lab-ready instruments backed by expert testing. Our testing protocols ensure that each piece of equipment—regardless of type—is safe, accurate, and dependable from day one.

    Whether you're equipping a startup lab or expanding a high-throughput facility, you can count on our refurbished laboratory equipment to perform with precision and reliability.

    Refurbishment Protocol for Used Laboratory Equipment from American Instrument Exchange

    At American Instrument Exchange, every piece of used laboratory equipment we offer undergoes a multi-step refurbishment process. Whether it's an analytical balance, centrifuge, freezer, oven, or any other essential lab instrument, our goal is to restore each unit to peak performance—ensuring accuracy, safety, and long-term reliability in scientific, clinical, industrial, and academic environments.

    Why Choose Refurbished Lab Equipment from American Instrument Exchange?

    • Thoroughly tested for performance, precision, and safety
    • Backed by a warranty
    • A cost-effective alternative to new equipment
    • Environmentally sustainable through equipment reuse and waste reduction
    • Serviced by expert technicians with decades of laboratory equipment experience

    Step-by-Step Refurbishment Protocol

    Every instrument and system refurbished at American Instrument Exchange follows a detailed, industry-aligned process:

    1. Initial Intake & Inspection

    • Complete visual and structural inspection for cosmetic damage, wear, or corrosion
    • Mechanical assessment of hinges, seals, fasteners, motors, and moving parts
    • Missing components and damaged items are documented for repair or replacement

    2. Cleaning and Decontamination

    • Full internal and external cleaning using non-abrasive, lab-safe solutions
    • Removal of biological, chemical, or particulate contamination
    • Disassembly and cleaning of removable parts such as trays, shelves, and filters

    3. Mechanical and Electrical Repair

    • Replacement or repair of worn or broken mechanical parts
    • Evaluation and servicing of control panels, sensors, switches, and displays
    • Testing and repair of electrical wiring, fuses, circuit boards, and power supplies

    4. Functional System Testing

    • Assessment of all major functions specific to the equipment type (e.g., speed, temperature, force, weight, timing)
    • Operation of control interfaces, programming menus, and digital displays
    • Verification of stabilization time, responsiveness, and user input reliability

    5. Testing and Performance Verification

    • Testing of internal sensors, controllers, and measurement systems using certified tools
    • Multi-point testing to ensure repeatability, accuracy, and performance consistency
    • Confirmation of user-defined setpoints, timing sequences, or programmable cycles

    6. Safety and Compliance Checks

    • Testing of safety interlocks, alarms, and over-limit protection systems (as applicable)
    • Electrical safety inspections, including grounding and insulation verification

    7. Final Quality Assurance and Documentation

    • Full operational testing under simulated lab conditions
    • Completion of performance benchmarks, testing  results, and repair logs
    • Final cleaning and visual inspection

    Trust the Experts at American Instrument Exchange

    With over 50 years of experience in the laboratory equipment industry, American Instrument Exchange is a trusted leader in high-quality refurbished lab instruments. Our refurbishment protocols ensure that every piece of equipment we sell is lab-ready—offering the precision, performance, and durability your team can count on.

    Whether you’re outfitting a new lab or expanding an existing operation, choose American Instrument Exchange for tested, warrantied, and cost-effective laboratory equipment.

    Warranty Information

    All used equipment sold by American Instrument Exchange is refurbished/reconditioned, tested to meet specifications, cleaned, and comes with a 90-day warranty from the date of shipment unless otherwise specified. New products include a warranty from the manufacturer. Your warranty is only valid if you have paid your invoice. If your invoice is over 30 days old, warranty work will not be performed until your invoice is paid in full.  American Instrument Exchange is not liable for any special or consequential damages that result from the use of, or the inability to use, the materials on this site or the performance of the products,

    Exceptions include international sales and items that are agreed to be sold with a lesser warranty or items that are agreed to be sold “as is.”

    Should there be visible shipping damage to packaging or concealed shipping damage to item(s) supplied, buyer must communicate such damage to the delivering entity or carrier upon receipt first and to American Instrument the same day item is accepted / signed for. Failure to do so voids warranty. Customer decision to involve / procure third party or OEM service other than American Instrument or AIE assigned vendors to resolve in-warranty instrument failure or defect without first placing a service call to American Instrument voids warranty.

    Return & Cancellation Policy

    American Instrument Exchange will authorize the return of and issue a full refund for any equipment that is not working as represented and could not be replaced or repaired to the customer’s satisfaction by AIE or a representative of AIE during the warranty period. Returns without prior authorization and an RMA number will not be accepted. 

    Customers are responsible for proper packaging of the equipment and all included accessories. American Instrument will pay for insurance and shipping costs. Non-inventory items bought specifically to fill customer orders may possibly be returned, but on a case by case basis.

    Customers who cancel orders after refurbishing has begun or after delivery where there are no equipment performance issues may be subject to a Restocking/Cancellation Fee of 20% or more and responsible for shipping costs for both the delivery and return.

    Ongoing and Extended Support Options

    American Instrument Exchange is able to provide additional repair and support services outside the warranty terms for most products that sell.

    For biosafety cabinets, clean benches, chemical fume hoods, and other clean air products our team at AIE Laboratory Services can provide certifications, repairs, decontaminations, and other services for customers throughout New England, and guidance and limited technical assistance for any customers in the US and Canada for new or refurbished biosafety cabinets purchased from American Instrument Exchange.

    For all other products, the repair service team at American Instrument Exchange can provide both field and depot repair evaluations. We can easily schedule and coordinate the pick-up and transportation of your malfunctioning equipment. By offering hourly rates lower than most OEM service providers and eliminating travel time for technicians, we help reduce repair costs. Furthermore, our lab depot repair service minimizes or eliminates scheduling delays. Our experienced service technicians are qualified to restore your equipment to factory specifications.

    Please contact our team at info@americaninstrument.com for more details.

    FAQ

    Does the equipment come with a warranty?

    Yes, all equipment from American Instrument Exchange comes with a warranty.
    Used/reconditioned/refurbished equipment is tested to make sure it operates to the manufacturer's specifications and comes with a 90-day warranty (unless otherwise noted). New equipment comes with a warranty from the manufacturer.

    How do you test and recondition the equipment?

    Testing requirements vary across all the equipment categories we sell. Temperature controlled units are tested with NIST traceable probes and data loggers. Gaskets, external housing, glass, handles, controls and control screens are all thoroughly inspected for integrity and functionality.
    We test all equipment using the manufacturer's parameters and specifications to confirm that the unit operates properly.

    How do products ship from American Instrument Exchange?

    We can ship products both nationally and internationally using a well-established network of transporters. Smaller items will ship via UPS. Larger equipment will be palletized and shipped either LTL or air-ride, depending on the specific equipment and/or delivery requirements.

    Return and order cancellation policy

    American Instrument Exchange will accept the return of any product that is not working as represented and could not be replaced or repaired to the customer's satisfaction during the warranty period. Customers who cancel orders after refurbishing has begun will be subject to a cancellation and restocking fee of between 20% and 40%.

    Are discounts available for educational or non-profit institutions, or for bulk purchases?

    Yes – call or email us today with a list of equipment you're looking for and we can potentially put together a quote that includes a discount.

    How does your price matching policy work?

    We strive to keep our pricing competitive and reasonable. If you find comparable items for sale at a lower price from other vendors please send us a link and or quote for the item and we'll do our best to match or beat the price.

    Can I see the equipment in person before committing to a purchase?

    Customers are welcome to make an appointment to view equipment in our warehouse. Given our workload we may not be able to test or clean the equipment prior to your arrival if you have not committed to an order.

    1023 Western Avenue is a working warehouse, not a showroom, and customers should dress appropriately and wear closed toe shoes.

    Can I ship products that I purchased elsewhere to American Instrument for repair?

    Yes – please see our repair services page for more information.