200ºC to -80ºC
Precision calibration of thermometers calls for the use of stirred liquid calibration baths. The new Hydra models set new standards in terms of price to performance ratio. Now Calibration Engineers and Metrologists can choose from a range of baths that offer good immersion depth, parallel tube action, giving the best uniformity and smallest calibration uncertainties, and wide temperature ranges.
Hydra offers these features in a new price class, don't settle for a bath with shallow immersion or simple stirred action when with these baths provide good depth of immersion and good temperature uniformity.
The immersion depth of 300mm allows the requirements of "Supplementary Information to the ITS-90" to be met. This publication from BIPM recommends immersion depths of 15 to 20cm from -50ºC to 50ºC, and from 20 to 27cm at 200ºC. Many baths in this price range are simply not deep enough to meet this requirement. Rather than simply stirring a square tank of liquid the Hydra uses parallel tube action for superior temperature uniformity. The calibration volume is cylindrical to suit thermometers, not a large square tank. The bath is filled with just 5 litres of liquid reducing filling andongoing cost of ownership as liquids are replenished. The 798H features a cooling coil which can beattached to an external source of either cold water or gas to further reduce cool down times.
Accessories allow a wide range of thermometers, for example, to be readily clamped by the Sensor Support and ITS-90 fixed points cells are accommodated with the adjustable cell holder.
Key Features...
- Parallel Tube Action...
Liquid flows up the rear volume of the bath and down the working volume. This action creates very small vertical and axial gradients. This gives the smallest overall uncertainties.
- Heating...
All heating is outside the container. By using a large area nickel foil heater the complete bath wall is heated uniformly.
- Cooling...
The cooling is built-in and also surrounds the calibration volume creating a low temperature ambient in which the heater can function efficiently.
- Wider Temperature Range...
A unique cooling system cools the unit as well as enabling the bath to heat up to 125ºC (121ºC is a key sterilization temperature).
- Commercial Grade Chillers...
The chillers are one third horse power commercial grade units, not cheaper domestic grade as used by some manufacturers.
- Stability...
Better than ±0.01ºC over the complete temperature range.
- Calibration Depth...
Double the depth of some baths. The Hydra Range has up to 300mm depth of immersion.
- Circular Design...
The circular design eliminates 'cold corners' found in tank shaped calibration baths.
- Fast Cool Down...
The Hydra cools from ambient to -80ºC in just 180 minutes.
Good Immersion Depth, reducing stem conduction errors Parallel Tube Action, giving the best uniformity and smallest calibration uncertainties Wide Temperature Ranges, -80ºC to 200ºC
