Abstract: A test chamber that is capable of operating in a mode where the temperature of the chamber is efficiently cooled without removing a substantial amount of moisture from the air. In one aspect, the test chamber includes a structure defining a work space having air, and a temperature control system (e.g., a refrigeration system having a compressor, a condenser, and an evaporator valve). The temperature control system includes a heat exchanger (e.g., an evaporator) positioned to communicate with the air in the work space, a source of cold fluid (e.g., a compressed, condensed, and throttled refrigerant) coupled to the heat exchanger, a source of hot fluid (e.g., compressed refrigerant gas) coupled to the heat exchanger, and a controller for controlling a mixture of cold fluid and hot fluid entering the heat exchanger (e.g., by adjusting a cold fluid valve and/or a hot fluid valve).

Abstract: A thermal cycling system includes a structure defining a load space, a heating assembly positioned to heat to the load space, and a cooling assembly positioned to cool the load space. The cooling assembly includes a refrigeration circuit and a banking circuit. The refrigeration circuit has a compressor, a refrigeration condenser, a first refrigeration evaporator in direct thermal communication with the load space, a second refrigeration evaporator in parallel with the first evaporator, and primary refrigerant circulating throughout the refrigeration circuit. The banking circuit is gravity fed and includes a banking condenser, a banking evaporator positioned to cool the load space, and a banking refrigerant circulating throughout the banking circuit. The banking condenser includes a collection reservoir to store liquid banking refrigerant and is in thermal communication with the second refrigeration evaporator.

Abstract: A thermal cycling system includes a structure defining a load space, a heating assembly positioned to heat to the load space, and a cooling assembly positioned to cool the load space. The cooling assembly includes a refrigeration circuit and a banking circuit. The refrigeration circuit has a compressor, a refrigeration condenser, a first refrigeration evaporator in direct thermal communication with the load space, a second refrigeration evaporator in parallel with the first evaporator, and primary refrigerant circulating throughout the refrigeration circuit. The banking circuit is gravity fed and includes a banking condenser, a banking evaporator positioned to cool the load space, and a banking refrigerant circulating throughout the banking circuit. The banking condenser includes a collection reservoir to store liquid banking refrigerant and is in thermal communication with the second refrigeration evaporator.

Abstract: A test chamber that is capable of operating in a mode where the temperature of the chamber is efficiently cooled without removing a substantial amount of moisture from the air. In one aspect, the test chamber includes a structure defining a work space having air, and a temperature control system (e.g., a refrigeration system having a compressor, a condenser, and an evaporator valve). The temperature control system includes a heat exchanger (e.g., an evaporator) positioned to communicate with the air in the work space, a source of cold fluid (e.g., a compressed, condensed, and throttled refrigerant) coupled to the heat exchanger, a source of hot fluid (e.g., compressed refrigerant gas) coupled to the heat exchanger, and a controller for controlling a mixture of cold fluid and hot fluid entering the heat exchanger (e.g., by adjusting a cold fluid valve and/or a hot fluid valve).

Abstract: A universal access port includes a specific size opening that is formed through a wall of a conditioning enclosure and located at a specific distance from a floor or mounting surface. The opening is preferably rectangular in shape, but other shapes may also be used. When not in use, the universal access port is covered with a sealing panel. Insertable devices may be efficiently inserted and removed from the universal access port. A perimeter of the insertable device is sized to be sealable inserted into the universal access port. Each insertable device preferably seals with an exterior and interior wall of the conditioning enclosure. Some insertable devices include fixturing devices, windows, manual manipulation devices, junction devices, hinged access doors, wire access devices, temperature modifying devices or air circulation devices.

Abstract: A universal access port includes a specific size opening that is formed through a wall of a conditioning enclosure and located at a specific distance from a floor or mounting surface. The opening is preferably rectangular in shape, but other shapes may also be used. When not in use, the universal access port is covered with a sealing panel. Insertable devices may be efficiently inserted and removed from the universal access port. A perimeter of the insertable device is sized to be sealable inserted into the universal access port. Each insertable device preferably seals with an exterior and interior wall of the conditioning enclosure. Some insertable devices include fixturing devices, windows, manual manipulation devices, junction devices, hinged access doors, wire access devices, temperature modifying devices or air circulation devices.

Abstract: A universal access port includes a specific size opening that is formed through a wall of a conditioning enclosure and located at a specific distance from a floor or mounting surface. The opening is preferably rectangular in shape, but other shapes may also be used. When not in use, the universal access port is covered with a sealing panel. Insertable devices may be efficiently inserted and removed from the universal access port. A perimeter of the insertable device is sized to be sealable inserted into the universal access port. Each insertable device preferably seals with an exterior and interior wall of the conditioning enclosure. Some insertable devices include fixturing devices, windows, manual manipulation devices, junction devices, hinged access doors, wire access devices, temperature modifying devices or air circulation devices.

Abstract: A universal access port includes a specific size opening that is formed through a wall of a conditioning enclosure and located at a specific distance from a floor or mounting surface. The opening is preferably rectangular in shape, but other shapes may also be used. When not in use, the universal access port is covered with a sealing panel. Insertable devices may be efficiently inserted and removed from the universal access port. A perimeter of the insertable device is sized to be sealable inserted into the universal access port. Each insertable device preferably seals with an exterior and interior wall of the conditioning enclosure. Some insertable devices include fixturing devices, windows, manual manipulation devices, junction devices, hinged access doors, wire access devices, temperature modifying devices or air circulation devices.

Abstract: A universal access port includes a specific size opening that is formed through a wall of a conditioning enclosure and located at a specific distance from a floor or mounting surface. The opening is preferably rectangular in shape, but other shapes may also be used. When not in use, the universal access port is covered with a sealing panel. Insertable devices may be efficiently inserted and removed from the universal access port. A perimeter of the insertable device is sized to be sealable inserted into the universal access port. Each insertable device preferably seals with an exterior and interior wall of the conditioning enclosure. Some insertable devices include fixturing devices, windows, manual manipulation devices, junction devices, hinged access doors, wire access devices, temperature modifying devices or air circulation devices.

Abstract: A refrigeration system is provided having refrigerant flowing therethrough. The refrigeration system provides temperature and humidity cooling within a chamber. The refrigeration system includes a compressor having an input and an output and an evaporator coil in communication with the chamber. A single expansion valve is provided in the input line to the evaporator coil for controlling the flow rate of the refrigerant delivered thereto and for limiting the pressure of refrigerant delivered to the input of the compressor.

Abstract: A testing apparatus is provided for testing a product in various climatic conditions. The testing apparatus includes a testing cabinet defining a first testing chamber for receiving the product therein and a vibration chamber. A vibration table is positioned within the testing apparatus and has an upper surface communicating with the testing chamber and a lower surface. A plurality of vibrators are operatively connected to the lower surface of the vibration table and are disposed in the vibration chamber. A climate control structure communicates with the vibration chamber for controlling the environment thereof.

Abstract: A testing apparatus is provided for testing a product in various climatic conditions. The testing apparatus includes a testing cabinet defining a first testing chamber for receiving the product therein and a vibration chamber. A vibration table is positioned within the testing apparatus and has an upper surface communicating with the testing chamber and a lower surface. A plurality of vibrators are operatively connected to the lower surface of the vibration table and are disposed in the vibration chamber. A climate control structure communicates with the vibration chamber for controlling the environment thereof.

Abstract: An apparatus for conducting environmental tests on a device and which incorporates an improved transfer mechanism is provided. The apparatus includes a cabinet defining first and second chambers therein. An insulation wall extends between the testing chambers and has an opening therein so as to allow passage between the first and second testing chambers. The transfer mechanism includes a frame structure positioned within the cabinet for supporting a basket which carries the device to be tested. The basket is slidable along the supports of the frame structure for carrying the device between the first and second testing chambers.

Abstract: An apparatus is provided for conducting environmental tests on a device. The apparatus includes a cabinet defining a testing chamber for receiving the device therein. Control structure, operatively connected to the cabinet, varies the environmental conditions within the testing chamber to a user desired environment. An isolation structure is provided for isolating the device within the testing chamber and preventing electromagnetic and radio frequency waves from passing therethrough.

Abstract: A cascade refrigeration system is provided. The cascade refrigeration system includes a low stage having a first refrigerant flowing therethrough and a high stage having a second refrigerant flowing therethrough. The low stage includes a compressor and evaporator coils. The input of the evaporator coils is operatively connected to the output of the compressor by an input conduit and the output of the operator unit is operatively connected to the input of the compressor by an output conduit. A bypass line has an input in communication with the input conduit and an output in combination with the output conduit. A bypass heat exchanger effectuates the heat exchange relationship between the first refrigerant flowing through the bypass line and the first refrigerant flowing through the input conduit.

Abstract: The invention is an improvement in a thermal stress screening system of the type using a single type of liquid for alternately transferring heat to and from the product. In the improvement, the product is confined in a single chamber during alternate heat transfer. That is, the system provides "one chamber" thermal stress screening. The system includes a plurality of tanks, one each for hot and cold liquid, and a heat exchanger associated with each tank so that the liquid in a tank is maintained at the proper temperature for stress screening. An improved method for thermally stress screening products, e.g., printed circuit boards, includes the steps of placing the product in a chamber, flowing cold liquid into the chamber, draining the cold liquid from the chamber and flowing hot liquid into the same chamber.

Abstract: A cascade refrigeration system is provided. The cascade refrigeration system includes a low stage having a first refrigerant flowing therethrough and a high stage having a second refrigerant flowing therethrough. The low stage includes a compressor and evaporator coils. The input of the evaporator coils is operatively connected to the output of the compressor by an input conduit and the output of the operator unit is operatively connected to the input of the compressor by an output conduit. A bypass line has an input in communication with the input conduit and an output in combination with the output conduit. A bypass heat exchanger effectuates the heat exchange relationship between the first refrigerant flowing through the bypass line and the first refrigerant flowing through the input conduit.