Laser flash photolysis (laser flash photolysis) is used to observe a series of changes and reactions that occur in the transition from the ground state S0 to the excited state Sn after the molecule has been excited by light.
It mainly consists of an excitation light source, a detection light source, a signal detection system and a data processing system. It is an effective tool to study the transition reaction intermediates such as singlet excited state and triplet excited state, free radicals, and positive and negative ions in the reaction process through the state spectrum and the corresponding kinetic decay curve.
Operating principle of the laser flash device
The laser flash device emits an alternating high voltage (1840 volts) with a modulation frequency of 500 Hz from the power supply to ignite the helium-neon Laser tube, the red laser beam emitted from the laser tube is seen as rectilinearreference is used after being reflected by the prism, the small eyepiece converges and the semi-transparent mirror rotates; p>
The adjustment is then made via the inner focus mirror. The beams, focused on targets at different distances, can be emitted from the objective lens and received by the photoelectric receiver (consisting of nine photocells) installed on the working machine, converted into electrical signals, and then frequency-selected and amplified to light up the nine photocells bring. One-to-one corresponding indicator lights show the orientation of the machine head.
When the laser beam hits the center of the photocell, the indicator light in the center lights up. This indicates that the position of the machine is correct and no signal is sent to the automatic control circuit at this time.
When the light beam hits a photocell next to it, a Signal sent to the indicator light and automatic control circuit to operate the automatic control system until the machine returns to the correct position.
The laser flash instrument is an instrument that uses the laser beam as a collimation line to control the forward direction of construction machinery (such as roadheaders).
The increasingly used tunnel boring machine (TBM) includes the laser guide, the inclinometer for measuring the position of the head of the roadheader and the guidance system of the roadheader consists of ultrasonic range finder, target, control unit, Screen monitor, computer and printer.