Q. How long will the battery last?

A. The battery life is a function of many factors, mainly how often the sensor takes data, but also length of data record, quality of radio link, excessive temperatures, and number of repeaters. Example: An accelerometer configured to sample data for an 800-line FFT, eight times per day, would have an expected battery life of over 3 years. For further information, refer to the technical brief, "Battery Life Application Note"

Q. How is the sensor calibrated?

A. The sensor is factory calibrated and will not require field calibration. The calibration values are stored within the sensor's nonvolatile memory. Each accelerometer is calibrated so the accuracy is about +/- 1%.

Q. How will temperature changes affect the sensor?

A. The sensor is corrected for temperature internally in the microprocessor, so normal temperature variations (0º to 155º F) will not affect the reliability.

Q. What is the lowest speed that the sensor can detect?

A. 0.5 Hz or 30 CPM

Q. What is the fastest speed that the sensor can detect?

A. 10,000 Hz or 600,000 CPM

Q. Is the radio licensed?

A. No. The 902-928 MHz range is license free ISM band as specified by the FCC.

Q. How does the Maintenance Watchdog™ radio system compare to other radios, such as Blue Tooth or 802.11b?

A. The carrier frequencies (2.4 GHz) used by Blue Tooth and 802.11b radios are substantially higher than the 902-928 MHz frequencies in the Maintenance Watchdog System and the processing tasks are much more complex. Because of these two factors, as well as others, a Bluetooth chipset uses on average 30-40 mA of current consumption, as compared to 1 mA of the Maintenance Watchdog System.

The primary advantage of the Bluetooth and 802.11b radios is data speed (about 700 Kbytes/sec versus about 100 Kbytes/sec). While this advantage is very important for devices such as wireless modems or computer printers, industrial sensors have other considerations, particularly battery life.

Q. What is the range of the sensor to the access point?

A. The nominal range of the sensor to Network Access Point is 75 yards.  Repeaters can increase the range of the system.

Q. Can the access points work on my existing LAN system?

A. Yes. The access points are Novell NE 2000 compatible and have an extremely small footprint on the network. The unit features typical 10 base T accessibility so the distance is not limited within your factory.

Q. Will the sensor get confused about which access point it needs to communicate?

A. The wireless system is overlapping and error tolerant, so there will be no confusion. If an access point goes offline, the sensors assigned to it will search for an active access point. The network is dynamic and automatically reconfigurable.

Q. How will obstructions affect the distance?