Conditioning
Chamber air is recirculated by one or more high volume, stainless steel axial fan(s) discharging through a hinged rear mounted guard and diffuser baffle to create a uniform environment around your test objects. The fan is driven by a vertically mounted motor with dual ball bearing races, connected by a large diameter extended stainless steel shaft. Fast-response open type heaters, located behind a radiation baffle, raise chamber temperature as required.
Cooling, Wide Range
A proportionally controlled cascade, two compressor, refrigeration system utilizing modern environmentally friendly refrigerants cools the workspace. The system includes automatic hot gas bypass and suction cooling unloading as well as Bemco's exclusive, high performance coaxial cascade heat exchanger. All systems are water cooled, have thermal and current sensors on each compressor as well as numerous safety and reliability protection systems for dependable operation.
Cooling, Narrow Range
A proportionally controlled single stage, one compressor refrigeration system utilizing modern environmentally friendly refrigerants cools the workspace. The system includes automatic hot gas bypass and suction cooling unloading. All systems are water cooled, have thermal and current sensors on each compressor as well as numerous safety and reliability protection systems for dependable operation.
Construction
FHC Series chambers include a 304 Series stainless steel welded liner with high temperature fiberglass insulation. No asbestos is used in chamber construction. Outer cases are fabricated from cold rolled steel finished in Bemco Blue. Chamber doors feature Bemco's plug door to minimize problems with expansion and contraction on the door face and dual gaskets to greatly reduce thermal losses near the door face. An over-center Bemco cam-type latch seals the door.
Safety Systems
All systems have thermal and current sensors on the compressor(s), charging valves, and a sight glass as well as numerous safety and reliability protection systems for dependable operation. All electrical wiring meets the United States National Electric Code. UL and CSA approved components are used where possible.
Controls
Each Bemco FHC chamber is furnished with a microprocessor based, programmable 1/4-DIN, solid state 256-step ramping controller which includes a 4-line LCD interface display and a large red LED display. Temperature inside the FHC chamber is sensed by a precision thermocouple. An RS232 and RS485 interface is standard. Heaters are interlocked with a separate heavy duty power contactor and a factory preset high temperature safety control.
Thermal Performance
Units are available with average heating and cooling rates in excess of 5 C / minute (9 F / minute), 10 C / minute (18 F / minute) and 15 C / minute (27 F / minute) over the temperature range of -55 C (-67 F) to +177 C (350 F) Slightly reduced cooling rates are offered to -73 C (-100 F) All systems utilize mechanical cooling exclusively to produce these cooling rates.
+ or - 1 C (+ or - 1.8 F) guaranteed control, + or - 0.5 C (+ or - 0.9 F) typical.
Optional Equipment
- Window and interior light. Window sizes are 12" x 12" and 18" x 18" clear viewing area.
- Access Ports. Sizes are 2", 3", 4" and 6." One 3" access port in the left wall is provided with each chamber.
- Casters, four swivel type with locks.
- Shelf pilasters and wire-type stainless steel shelves.
- LN2 boost cooling with vent for extra or back-up cooling.
- GN2 gas purge with pressure regulator, gauge, flow measuring and regulating valved rotameter, and vent.
- Desiccant drier purge with dual tower 10 cfm desiccant drier, pressure regulator, gauge, flow measuring and regulating valved rotameter and vent.
- Two refrigeration gauges mounted in the refrigeration package available with or without isolation valves for single stage systems and four refrigeration gauges, two per compressor, for cascade systems.
Optional Instruments
Controls are mounted on the side to prevent dripping from damaging the instruments. Available instruments include:
- Microprocessor-based, FM Approved high over-temperature safety control.
- Set of two, one high and one low microprocessor-based, FM Approved temperature safety controls.
- Remote control over an Ethernet Link.
- Custom fixturing, load boards, and card cages to match your load.
- 12 inch, chart printing, circular recorder.
- Strip chart recorder.
Available Literature Includes:
Bemco FHC Series, High Capacity Temperature Chambers. Document
is triple fold front and back, 2 pages, 349 KB download.
Bemco Temperature Conversion Table. Temperature conversion chart
for -273.15 C (absolute 0) to +548.89 C (1020 F) in 10 degree increments.
Document is 1 page, 336 KB download.
The systems described above are our Standard Models. We make custom equipment to your specifications. If you have any questions, need assistance in preparing a specification, or have a technical problem you want help with, we are ready. Our quotations and advice are free.
