388
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
be conducted with a code, which is sent into the PPU through a serial
line.
(e) The connection unit provides exchange through the serial line at a
speed of 9600 bit/s.
(f) The high-voltage PMT power supply provides voltage of 1600 V, and
adjustment range is lower than 10%.
(g) The power supply provides the operation of the above enumerated
units.
3.3. Photodiodes PD 2A or PD 7 are used as a photoelement in the power
indicator of laser radiation, and a needle indicator is used.
The needle indicator and the photoelements are put on the faceplate of the
device.
The electric part of the LS is situated in the PPU and consists of units of
signal processing, low voltage (LV) and high voltage (HV).
3.3.1. The signal processing unit (SPU) consists of the following units:
a PMT signal intensifier, a high-frequency (HF) filter, an analog–
digital converter (ADC), sequenced exchange with the PC.
3.4. Constructively, the LS is made in the form of a table device and has the
dimensions of 168 × 340 × 154 mm. The body of the device has an upper
removable cover, and when it is removed there is the access to the units and
mounting of the device. Location of the LS units is shown in Fig. 5.9b.
On the front panel of the LS (Fig. 5.10a), there is a main-electrical breaker,
an indicator “network,” an outlet of the light guide, an indicator head
and a photoreceiver of the power indicator; on the back panel of the
LS (Fig. 5.10b), there are a network connector, a network safety device
(common), a power indicator, a data receiving indicator, a ground clamp,
a PPU network safety device, a connector to a PC serial port.
3.4.1. The capacity of the analog–digital converter is 12 bits. The range of
the measured amplitudes is from 2048 to 2047 levels of the ADC.
3.4.2. The interface of connection with a PC is RS-232.
The exchange speed for data transmission
• into PC is 115,200 bit/s and
• from the PC is 9600 bit/s.
3.4.3. Programmable coefficients of PMT signal intensification have to
be 1, 2, 4, 8, 16.
4. Organization and operation of the laser specklometer.
The operation of the laser specklometer is provided by hardware and software.
4.1. Duration of registration of time intensity fluctuations of the speckle-field: In
low-frequency ones (1–62.5 Hz), it is not more than 8 s; in high-frequency
ones (5–2000 Hz), it is not more than 1 s.
5 Laser Specklometer, Speckle-Optical Diagnostics and Laser …
be conducted with a code, which is sent into the PPU through a serial
line.
(e) The connection unit provides exchange through the serial line at a
speed of 9600 bit/s.
(f) The high-voltage PMT power supply provides voltage of 1600 V, and
adjustment range is lower than 10%.
(g) The power supply provides the operation of the above enumerated
units.
3.3. Photodiodes PD 2A or PD 7 are used as a photoelement in the power
indicator of laser radiation, and a needle indicator is used.
The needle indicator and the photoelements are put on the faceplate of the
device.
The electric part of the LS is situated in the PPU and consists of units of
signal processing, low voltage (LV) and high voltage (HV).
3.3.1. The signal processing unit (SPU) consists of the following units:
a PMT signal intensifier, a high-frequency (HF) filter, an analog–
digital converter (ADC), sequenced exchange with the PC.
3.4. Constructively, the LS is made in the form of a table device and has the
dimensions of 168 × 340 × 154 mm. The body of the device has an upper
removable cover, and when it is removed there is the access to the units and
mounting of the device. Location of the LS units is shown in Fig. 5.9b.
On the front panel of the LS (Fig. 5.10a), there is a main-electrical breaker,
an indicator “network,” an outlet of the light guide, an indicator head
and a photoreceiver of the power indicator; on the back panel of the
LS (Fig. 5.10b), there are a network connector, a network safety device
(common), a power indicator, a data receiving indicator, a ground clamp,
a PPU network safety device, a connector to a PC serial port.
3.4.1. The capacity of the analog–digital converter is 12 bits. The range of
the measured amplitudes is from 2048 to 2047 levels of the ADC.
3.4.2. The interface of connection with a PC is RS-232.
The exchange speed for data transmission
• into PC is 115,200 bit/s and
• from the PC is 9600 bit/s.
3.4.3. Programmable coefficients of PMT signal intensification have to
be 1, 2, 4, 8, 16.
4. Organization and operation of the laser specklometer.
The operation of the laser specklometer is provided by hardware and software.
4.1. Duration of registration of time intensity fluctuations of the speckle-field: In
low-frequency ones (1–62.5 Hz), it is not more than 8 s; in high-frequency
ones (5–2000 Hz), it is not more than 1 s.