Dry bath temperature control and method

A dry bath comprising:

• a heat conductive block having a plurality of bores adapted to receive tubes containing samples of material;
• a heater mounted in heat transfer relation to the heat conductive block and operative when energized to add heat to the heat conductive block;
• a cooling device mounted in heat transfer relation to the heat conductive block and operative when energized to transfer heat from the heat conductive block;
• a temperature sensor mounted in heat transfer relation to the heat conductive block for sensing the temperature of the heat conductive block;
• and
• a heat controller connected to the heater, the cooling device and the temperature sensor and executing a control cycle of
• automatically detecting an increase in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature greater than the desired temperature;
• thereafter automatically cooling the heat conductive block to a temperature less than a desired temperature, thereby transferring more heat from the samples in the tubes than if the block were cooled to only the desired temperature, and
• thereafter automatically increasing the heat being applied to the block while heat continues to transfer from the samples to the block such that the block and samples simultaneously reach, and are maintained at, the desired temperature, the samples being cooled to the desired temperature more quickly than if the block was maintained at the desired temperature.

A method of controlling the temperature of samples in a plurality of tubes disposed in a heat conductive block of a dry bath, the block having a heater under control of a controller which is responsive to a temperature sensor mounted in a heat transfer relation with the heat conductive block, the method of operating the heater under control of the controller comprising:

• automatically heating the block to a desired temperature in the absence of the tubes in the block;
• thereafter automatically detecting a decrease in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature less than the desired temperature;
• thereafter automatically heating the heat conductive block to a temperature greater than the desired temperature, thereby transferring more heat to the samples in the tubes than if the block were heated to only the desired temperature;
• and
• thereafter automatically reducing the heat being applied to the block while heat continues to transfer from the block to the samples such that the block and samples reach, and are maintained at, substantially the desired temperature.

A method of controlling the temperature of samples in a plurality of tubes disposed in a heat conductive block of a dry bath, the block having a heater under control of a controller which is responsive to a temperature sensor mounted in a heat transfer relation with the heat conductive block, the method of operating the heater under control of the controller comprising:

• automatically heating the block to a desired temperature in the absence of the tubes in the block;
• thereafter automatically detecting a decrease in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature less than the desired temperature;
• and
• thereafter automatically controlling the operation of the heater to first, heat the block to a temperature in excess of the desired temperature and second, reduce the heat being applied to the block while heat continues to transfer from the block to the samples such that the block and samples simultaneously reach, and are maintained at, the desired temperature, the samples being heated to the desired temperature more quickly than if the block was maintained at the desired temperature.

A method of controlling the temperature of samples in a plurality of tubes disposed in a heat conductive block of a dry bath, the block having a heater under control of a controller which is responsive to a temperature sensor mounted in a heat transfer relation with the heat conductive block, the method of operating the heater under control of the controller comprising:

• automatically heating the block to a desired temperature in the absence of the tubes in the block;
• thereafter automatically detecting a decrease in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature less than the desired temperature;
• and
• thereafter automatically controlling the duty cycle of the heater to first, set the duty cycle be greater than a duty cycle determined by the function of the temperature difference between the temperature detected by the temperature sensor and the desired temperature, thereby heating the block to a temperature in excess of the desired temperature and second, set the duty cycle be equal to a duty cycle determined by the function of the temperature difference between the temperature detected by the temperature sensor and the desired temperature, thereby reducing the heat being applied to the block while heat continues to transfer from the block to the samples such that the block and samples simultaneously reach, and are maintained at, the desired temperature.

A method of controlling the temperature of samples in a plurality of tubes disposed in a heat conductive block of a dry bath, the block having a cooling device and a heater under control of a controller which is responsive to a temperature sensor mounted in a heat transfer relation with the heat conductive block, the method of operating the cooling device and the heater under control of the controller comprising:

• automatically bringing the block to a desired temperature in the absence of the tubes in the block;
• thereafter automatically detecting an increase in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature greater than the desired temperature;
• thereafter automatically cooling the heat conductive block to a temperature less than the desired temperature, thereby transferring more heat from the samples in the tubes than if the block were cooled to only the desired temperature;
• and
• thereafter automatically increasing the heat being applied to the block while heat continues to transfer from the samples to the block such that the block and samples reach, and are maintained at, the desired temperature.

A method of controlling the temperature of samples in a plurality of tubes disposed in a heat conductive block of a dry bath, the block having a cooling device and a heater under control of a controller which is responsive to a temperature sensor mounted in a heat transfer relation with the heat conductive block, the method of operating the cooling device and the heater under control of the controller comprising:

• automatically bringing the block to a desired temperature in the absence of the tubes in the block;
• thereafter automatically detecting an increase in the temperature of the block in response to the tubes containing samples being placed in the block, wherein the samples in the tubes have a temperature greater than the desired temperature;
• and
• thereafter automatically controlling the operation of the cooling device and the heater to first, cool the block to a temperature less than the desired temperature and second, increase the heat being applied to the block while heat continues to transfer from the samples to the block such that the block and samples simultaneously reach, and are maintained at, the desired temperature, the samples being cooled to the desired temperature more quickly than if the block were cooled to only the desired temperature.