Texas Instruments WRL-10 - Manual (Page 17)

Texas Weather Instruments, Inc. 17 WRL Instruction Manual
Calibration
The Weather Report comes pre-calibrated from the factory, but it is possible to
recalibrate most of the primary functions of the instrument using TWICAL program.
Barometric Pressure
Normally, barometric pressure is the only item that needs to be recalibrated (adjusting
for altitude). The proper local barometric pressure can be obtained from the local
news. Set the barometric pressure reading you obtained from the local media by
using the calibration mode function.
Temperature
If for some reason you suspect that the temperature is not calibrated properly, use a quality
bulb thermometer with which to calibrate the temperature. Remember that the WRL will be
most accurate near the temperature at which it was calibrated
.
Humidity Sensor Calibration
The humidity sensor is calibrated by inputting two voltages found on the humidity sensor
into the WRL. Humidity calibration factors can be entered by depressing select and
humdity hold at exacty the same time. The humidity calibration numbers are found on the
humidity/temperature sensor and on the back of the instrument console. These calibration
numbers are supplied to us by the manufacturer of the sensor and are normally not
changed.
Rainfall
The WRL is compatible with most rain collectors on the market today. Actual measurement
calibration is accomplished inside the rain collector by adjusting two stainless steel
screws.
Setting 0 turns the rainfall counter off. Setting 1 or 2 tells the WRL to react with one count
for every momentary switch closure of the rain collector.
Setting 3 tells the WRL to react with one count for every rain collector switch transition from
an open or closed state.
The rain measurement value tells the WRL how much rainfall to display for each count.
THE PROPER SETTING FOR THE TEXAS WEATHER INSTRUMENTS RAIN
COLLECTOR IS "2" FOR THE COUNT AND ".01" FOR THE MEASUREMENT.