The lightning package includes a mast mounted lightning sensor, mast clamp and a sensor intermediate cable. The lighting sensor is a Very Low Frequency receiver which digitizes lightning discharges and sends that information to the data logger which records and displays this data. The unit can detect and record up to 9999 discharges per minute.
The weather station displays, the lightning counts per minute in the BP/RH window. Normally, the current minute data is displayed. In the average mode the previous 1 minute count is shown. When the Average button is held, the 6 minute average count appears. The lunar tide cycle display is used to show an analog style logarithmic output of the lighting count. Note: This lightning sensor is not capable of predicting lightning, it is only capable of measuring lightning as it occurs.
The TWI Lightning Sensor must be mounted at the top of a grounded mast. The taller the mast and the better the earth grounding the further away lightning can be detected. A detection range of over 200 miles can be achieved depending on the installation.
Mount the Lighting Sensor one inch below and 180 degrees away from the wind sensor (refer to figure A) in order to gain the maximum distance between the two sensors. The top of the Lightning sensor must not be below any part of the grounded mast, doing so will shield the sensor from detecting lightning from that direction. Some installations might require a separate mast.
Note: On WLS-8000 installations both the TE wind sensor and the lightning detector require the very top of the sensor mast. We therefore suggest for maximum range of the lightning sensor that a separate mast be used for the lightning. It is possible to mount the lightning sensor below the TE wind sensor but the user should be aware that the lightning detection range will be affected especially in the direction of the mast.
Run the RG-58 coax (and other sensor cables) with the attached BNC connector down the mast, securing with the provided cable ties, into the junction box. Also run the intermediate RG-58 cable with attached BNC connector into the junction box. Plug both BNC connectors into the BNC “T” adapter located in the junction box. Please note that the T adapter is wired into the hose clamps in order to provide an earth ground to the system.
The Lightning Detector must have a good earth ground. We suggest at least a three foot copper grounding rod with heavy copper or aluminum bare wire going to the junction box.. Place the bare grounding wire between the junction box hose clamp and the mast for the best ground path.
Connect the intermediate BNC connector into the weather instrument console using the in-line BNC adapter that is provided.
Lighting Aux board drawing
Use TWI_LOG, or any communication program to access lightning data using the following commands
The “z” (lower case) command is used to output the accumulated lightning data for the current hour. At the end of the hour, the data will be logged if the hourly max count is greater than the counts per minute threshold. The threshold may be changed through the F5 routine in the TWI_LOG Software. The logged lightning data is written to the data logger memory a maximum of once per hour. It can be accessed along with other logged data using the T, B, P and N commands. See Communicating with the W… for more details.
mo/dy hr:mn max :00 :06 :12 :18 :24 :30 :36 :42 :48 :54
xx xx xx xx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx
mn minute of max count
max max count per minute
:00 average count from :00 to :05
:54 average count from :54 to :59
The “Z” (upper case) command is used to output current lightning data.
yr/mo/dy hr:mn:sc cur cnt lst avg max min
xx/xx/xx xx:xx:xx xxxx xxxx xxxx xxxx xxxx :xx
yr year, current
mo month, current
dy day, current
hr hour, current
mn minute, current
sc second, current
cur count, current minute accumulation
cnt count, current full minute
lst count, prior full minute
avg count, 6 minute average
max count of max in current hour
min minute of max in current hour