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Thermo Scientific™ Forma™ Environmental Chamber Model 3911, 311.5 L, Stainless Steel

Temperature Range: 0°C to 60°C; Relative Humidity (RH): Ambient to 95% at 37°C; Light: Optional Interior Lighting

Supplier:  Thermo Scientific™ 3911

Catalog No. 13-987-065

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Perform a variety of applications withThermo Scientific™ Forma™ environmental chambers, which can be configured for a variety of purposes and are available in multiple capacities. With a wide range of accessories and years of experience in constructing cabinets, we can construct units to match your most stringent applications.

Broad Range of Features and Controls:

  • Wide temperature range of 0° to 60°C that enhances the flexibility of the unit
  • Relative humidity control via steam generator from above ambient to 95% at 37°C (not available w/Cat. No. 3920)
  • Sophisticated digital controls
  • Programmable ramp and soak cycles for temperature and RH†
  • Durable cabinets with true laminar airflow through side plenums for extremely tight uniformity
  • Phenolic-coated evaporator for use in applications that create corrosive byproducts
  • Manual control of defrost and refrigeration cycles
  • Visible/audible safety alarms alert to over- and undertemperature conditions, deviation of humidity from set parameters (except Model 3920)

Durable Construction:

  • Cold-rolled steel, powder-coated cabinet
  • 2″ (5.1cm) thick, CFC-free, foamed-in-place polyurethane insulation
  • Stainless-steel interior with solid stainless-steel adjustable shelves
  • Directed horizontal airflow system for excellent uniformity
  • Locking swivel casters for easy mobility during installation and cleaning
  • Leveling feet for stability and added safety in the lab

Broad Range of Options:

  • Interior lighting for Models 3920, 3940 and 3949 (Optional)
  • Reinforced shelving and flooring for heavy loads
  • Heatless dryer for lower humidity levels
  • Access ports for probes, sensors
  • Interior convenience receptacles
  • CO2 (IR sensor)
  • 6″ and 12″ temperature chart recorder
  • Other custom options available

Compatible with:

  • Recorders (197075, 198036, 198039, 198042, 201144, 201145, 201146, 201147)
  • Reach-In/Environmental Chamber Solid Stainless-steel Shelf (224139)
  • Reach-In/Environmental Chamber Perforated Stainless-steel Shelf (224155)
  • Reinforced Stainless-steel Shelf (224161)
  • Fixed Reinforced Stainless-steel Shelf for two shakers (1900005)
  • Stainless-steel Door Glass Cover, factory installed (190591)

Recommended for:

Ideal for growth, stability and shelf-life testing applications

Ordering Information

† Humidity controller available on 3940/3949, 3911/3913 only




11 cu. ft.
311.5 L
IR Sensor
Powder-coated Cold Rolled Steel
Environmental Chamber
Digital, dual LED (direct set and read in % RH)
Bulk polymer
Water Inlet Gravity to 40psi
CFC-free, R134A
±0.3 at 25° to 37°C
50kilohm to 1megohm resistance
38 in.
96.5 cm
51.5 in.
130.8 cm
32 in.
81.3 cm
208/220 V, 60 Hz
15 A
Stainless Steel
Optional Interior Lighting
3 supplied/11 max.
0°C to 60°C
Digital Dual LED
Microprocessor, PID
Steam generator; initial fill approx. 1 qt. (1L)
Temperature ramp and soak, up to 24 steps
±0.1 at 25° to 37°C
0.25 gal./hr. input water volume
27 x 31 x 24 in. (68.6 x 78.7 x 60.9 cm)
31 in.
78.7 cm
24 in.
60.9 cm
27 in.
68.6 cm
208/220 V
60 Hz


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