°C or °F and thermal radiation in W/M² or BTU/Hour/FT The 774 can be left for extended periods to log the above parameters at a user set interval (10 seconds to 1 hour). The saved data can then be transferred to a computer for display, graphing etc.
BASIC OPERATION To take a reading the appropriate yellow button is pushed depending on the measurement required and the reading is taken. UV= Ultra Violet (µW/lumen or mW/M Vis= Visible light (Lux or Foot-candles) T= Temperature (Centigrade or Fahrenheit) IR= Thermal radiation (Infra Red) The unit automatically turns off 10 seconds after the button is released unless a button is held down for over 5 seconds, this will cause readings to be taken continuously until a button is pressed.
The above format is slightly different for some parameters and can be altered by the user if required, see below. Set Button The blue Set button is used to access advanced functions, change units etc. If it is pushed once a menu similar to that below is shown: Max-Min>...
UNITS OF MEASUREMENT Ultra-Violet (UV) Traditionally UV has been measured in museums as the proportion of ultraviolet present. This result is useful for checking a particular lamp or window because the proportion of UV does not change with the distance from the light source. Using a simple rule the amount of UV on an object can be limited.
Visible Light This can be displayed either in Lux or Foot-candles. To change the units press Set\Units\Lux-Footcandl. A visible light readout is provided to control illumination and limit damage done by visible light. Normal museum light levels should be limited to 150-250 Lux. Once measurements have been made the light level can be altered if necessary and UV filters can be fitted on windows, fluorescent tubes or other UV producing light sources as required.
MAXIMUM AND MINIMUM The maximum and minimum values for each unit are displayed along with the day of the month and time the maximum or minimum occurred. The values can be reset by pressing Set\Max-Min\Reset (This equates to pressing Set 3 times).
DISPLAY Contrast The display contrast can be increased/decreased by pressing Set\Display\Contrast UP or DOWN. If this is done the menu continues to be displayed and the set button can be pressed repeatedly until the required contrast is achieved. Backlight The display backlight operation can be adjusted from the Set\Display menu as follows: Menu item Action...
DATA LOGGING Data logging is an optional extra. A standard unit can be upgraded to include data logging by returning it to the manufacturer. If data logging is not fitted then the relevant menu items are not displayed. If data logging is fitted “Data logging” is one of the options when the Set button is pushed.
"Logger/Set & Download" from the menu. Something similar to the following is displayed: If "Auto Download" is checked then any new data is downloaded as soon as contact is made with the logger. 3. Select Set\Data logging\Transmit on the 774.
Page 14
The infrared link can be closed by pressing the 'X' key on the 774 or closing the "Set & Download" window on the PC. If the 774 is just taken away without the link being officially terminated the computer will complain that it has lost communication, this does not matter.
Page 15
If power has been lost then the 774 may forget how many records it has saved and no data will be transferred. It is possible to force the 774 to transmit data by selecting “File\Get Data”...
At the time of writing Rview have been tested with Microsoft Windows 98 and 2000. To install the software run the installation program that is provided on a floppy disc or that has been downloaded from our web site (www.elsec.co.uk) and follow the instructions given. The installation file is called Rview21.exe or similar.
Viewing the Results using RView For more detailed information on RView see the help file. When RView is started an empty window is shown. One or more data files can be opened by selecting File\Open on the menu or pressing the appropriate button on the toolbar.
CLOCK The 774 has a built in clock, this is used to show the time of maximum and minimum values and for data logging. The date functions are valid until January 2098 so the unit is completely year 2000 compliant.
Software Version The internal software version is displayed when the 774 is turned on. A typical start- up message might be “ELSEC 774 V2.1”, in this case the software version is 2.1...
Temperature The 774 is fitted with a solid state temperature sensor that should not normally require calibration. The unit can be checked by putting it together with another, known accurate, temperature measuring device for at least an hour.
(e.g. ordinary filament light bulbs). Because the 774 has a cosine angular response it may give different readings to a type 762 which is relatively directional. In other words the 774 is more sensitive to light coming at an oblique angle than the 762.
SERVICE AND SUPPORT For support and repairs contact: Littlemore Scientific Engineering Railway Lane Littlemore Oxford OX4 4PZ Tel: 01865 747437 Fax: 01865 747780 Email: support@elsec.co.uk http://www.elsec.co.uk...
SPECIFICATIONS Method of radiation detection Twin silicon photodiodes connected to microprocessor. Visible wavelength range 400-700nM (CIE response). No correction required for different light sources. Visible power range 0.1 - 200,000 Lux (0.1 – 20,000 Foot-candles) UV wavelength range 300-400 nM UV power range 2 - 50,000 mW/M 0 - 10,000 mW/Lumen...
Need help?
Do you have a question about the 774 and is the answer not in the manual?
Questions and answers