
6772 Precision Calorimetric Thermometer
The Parr 6772 Calorimetric Thermometer is used to record all temperature readings and fully sequence the calorimetric test. The thermometer is equipped with a color touch screen display, supporting an intuitive graphical user interface. The temperature of the stirred water surrounding the bomb, as well as the calorimeter jacket temperature, is recorded. Real-time heat leak corrections are performed during the test by the thermometer, resulting in a fully corrected temperature rise measurement for each test run. The thermometer can also be connected to an Ethernet network (LAN) and incorporates web, FTP, and VNC servers. The Parr Remote Interface Feature VNC server allows for remote operation of the calorimeter from a network connected PC running either MS Windows or a Linux operating system.
Dynamic Pressure Recording System
The Parr Dynamic Pressure Recording System can be used in conjunction with the detonation calorimeter in order to record the change in pressure in the bomb that accompanies a detonation. This system is designed to allow users to study pressure changes typically associated with the fast decomposition of materials used as explosives and is comprised of the following subsystems:
- The first subsystem includes a fast-time response dynamic pressure transducer with the associated signal conditioning electronics. The transducer is capable of recording pressures up to 10000 psi. The useable upper frequency limit for the transducer is 100 kHz. The minimum detectable pressure change is 0.5 psi. The accuracy is 1% of full scale. The time constant of the measurement system is on the order of 10 minutes. As a result, short-term static or “quasi-static” pressure measurements become feasible.
- The system also includes a high speed (200 kS/s), PC based (USB interface) data acquisition system, which is used to record the output of the transducer system. Data acquisition can be triggered or synchronized by the manual activation of the bomb ignition unit or firing set. Post triggered pressure data is saved to a PC disk file.
- A Windows™ based user interface program is provided with the system. The program is equipped to stream data to disk after the combustion event is initiated. The data can then be easily exported to a spreadsheet for further analysis and plotting.