| The Model 764 Environmental Monitor is a single instrument that enables measurement of the four parameters that cause most damage to buildings, valuable objects, documents etc: ultra-violet and visible radiation, humidity and temperature. For many years it has been recognised that one of the major causes of damage to museum objects and other antiquities is the fading and rotting effect of light on the object. The most damaging part of the illumination is its ultraviolet (UV) content. Since 1976 Littlemore Scientific (ELSEC) has been providing instruments that enable the conservator to measure the UV content of light and thereby protect valuable exhibits. Using the 764, measurements can be taken of the proportion of UV present (mW/lumen), the total amount of UV (mW/M), the amount of visible light present as Lux or Foot-candles. Temperature can be measured in C or F, humidity is shown as % Relative Humidity (%RH) and dew point. The displayed units can easily be changed by the user. Provision is made for user calibration of the RH sensor using saturated salt solutions. A calibration kit is available as an optional extra. Maximum and minimum values and their time of measurement are displayed for each parameter. Much trouble has been taken to make the 764 as easy to use as possible. Anyone can take measurements straight out of the box with little, if any, reference to the instruction manual. The appropriate button is pushed depending on the measurement required and the reading is taken. The unit automatically turns off 10 seconds after the last reading unless a button is held down for over 5 seconds, this causes continuous measurements to be taken until another button is pressed. The large 8 line display enables an easy to use menu system to select the more advanced functions, change units etc. Data Logging The optional data-logging function enables over 10,000 readings of all four parameters to be automatically taken at selectable intervals (every 10 seconds to 1 hour). The saved data can then be transferred to a computer by a wireless infra-red link (IrDA compatible). Many modern computers have an infra-red interface built in; for those that do not, adapters are available. When logging data the 764 can be turned off to save power and the built in clock will turn the unit on whenever a reading needs to be taken, this enables a 764 to be left taking readings for months at a time. Software is provided to save the logged data in a CSV format that can be accessed and displayed by many programs (e.g. Microsoft Excel). A seperate program allows the graphical display of the data. |
