OWL DC Voltage Data Logger 21© 2001 ... ACR Systems Inc.5 OWL DC Voltage Data LoggerFeaturesThe OWL DC Voltage Data Logger provides a versatile means of recording a variety of signals in asmall, water-resistant enclosure. It can be configured for easy interface with common transduceroutputs.5.1 DescriptionThe DC Voltage Logger can measure and record analog Direct Current voltage covering 32 rangesfrom 120mV to 38.4V full scale. The model available is the OWL-400.How it WorksThe logger uses a precision 2.5V reference voltage to convert the analog signal to a digital value. A setof voltage divider resistors on the front end (before the analog to digital conversion) allows for 16different input ranges. The voltage reference has its own 20:1 resistor divider network making a set oflow ranges. This doubles the number of selectable ranges to 32 in total. The digital values areprocessed into voltage units by an equation in TrendReader Software.5.2 Setup and UseThis section provides guidelines to follow to get started with the OWL DC Voltage Logger.1. Connect the cable supplied to the signal being measured - see Figure 4.12. Run TrendReader Software and communicate with the logger by double clicking on the com porticon and pointing the flashing wand at the logger's optical port. Once the Status menu is displayedselect the Setup option - see Figure 4.23. Make sure the DC Voltage equation is chosen. Then select a range that best fits the expected data- see Table 4-1. DC Voltage ranges are picked to match the transducers full scale output value. Forexample, if a transducer with a 0 to 5 volt output is used then range number 18 which measures upto 7.3 VDC gives the best resolution.