Droplet SP2 Manuale - Pagina 4

Sfoglia online o scarica il pdf Manuale per Strumenti di misura Droplet SP2. Droplet SP2 13. Beam-scan camera and software

Introduction

Optimum performance of the SP2 is obtained when the YAG laser beam is operating in the

TEM

mode. This is defined by a single laser beam spot which has a Gaussian profile. Higher-

order modes will have multiple spots, which may not affect the measurement of black carbon

incandescence but will almost certainly limit the utility of the scattering data collected. In cases

where very high-order modes are present, the incandescence data can also be compromised.

The SP2 beam scan camera and software is designed to facilitate observing and setting the

mode of the YAG laser in the SP2. The system consists of a Mightex CCD camera which has been

fitted with a high Optical Density (OD) filter. A mounting bracket allows the camera to be

mounted in the position normally occupied by the YAG power monitor on the SP2. The light-

intensity data from the camera is recorded and processed by a software package made by

Visulux, called vBeam. In the Windows 7 32-bit version, the vBeam software has code in it to

read only a camera with a specific serial number. If multiple units of the camera and software

are purchased, the installed software must be correlated with a given camera. With Windows 7

64-bit version and newer, the drivers should enable the software to find the correct serial

number of your camera automatically. In both versions of Windows 7, it is necessary to load the

software thru both USB ports so that the camera will be found by the system. If the software is

loaded into one port and the camera is plugged into the other USB port, the camera will not be

found.

Installation

For installation of the software, follow the instructions given in the Visulux manual. This manual

will discuss the installation of both the driver for the camera and the Visulux executable

software. In the setup of the Visulux software, one minor change from the default values is

recommended. The software will be installed in the folder Program Files/Visulux. Navigate to

the Visulux folder and open the file mightex.prop using Notepad. The following shows the

contents of this file. The default for the exposure time is 10000. This will result in saturation of

the camera response, and it is recommended that this be set at 5000 for a starting value. This

can be adjusted later as needed.

DOC-0175 Rev D