Davis Vantage Pro Information

The standard VP model, whether wireless or cabled, includes an anemometer and wind vane, outside temperature and humidity sensors, a rainfall gage (using a tipping bucket), indoor temperature and humidity sensors, and a barometer (the indoor sensors and barometer are located within the console, depicted in the above photograph). Several other data elements are calculated by the firmware in the console, including dew point, heat index, and wind chill (using the new NOAA/EC formula for units produced since late October 2001). The outside sensors are mounted together in what Davis calls the "Integrated Sensor Suite" (ISS). The outside temperature and humidity sensors as well as the transmitter in the wireless model are mounted underneath the rain gage, and the anemometer and wind vane are mounted opposite these sensors in a "clamshell" fashion. These two halves can be mounted separately using the included 40' 4-wire cable. This can be handy in mounting the anemometer up high and away from obstructions, and the rain gage near ground level. This makes for a very poor location for the transmitter, however. The ISS is solar powered, backed up by a supplied lithium battery. Time will tell on the longevity of the battery. The unit also tracks rainfall rate, and makes forecasts based on a proprietary algorithm using barometric pressure and trend, wind direction and wind speed, time of the year, temperature, and allegedly, latitude and longitude. (The use of latitude and longitude in the forecast have not been borne out by this user's experimentation. I input latitude and longitude for several dramatically different climactic zones, such as Palm Springs, California; Sitka, Alaska; and my own station's site in Northern Virgina. All three locations consistently provided identical forecasts.) Not only are relatively traditional forecast icons provided, but also a textual forecast that scrolls across the "ticker tape" display at the bottom of the screen upon demand. These forecasts are interesting and at least sometimes accurate, but one shouldn't base important decisions on their basis. Some of these forecasts get quite complex, such as "INCREASING CLOUDS AND COOLER. PRECIPITATION POSSIBLE WITHIN 6 HOURS AND WINDY, WITH POSSIBLE WIND SHIFT TO THE W, NW, OR N." Several "cutesy" messages will pre-emptively appear in the ticker tape display, such as "IT'S RAINING CATS AND DOGS" when rainfall rate exceeds .3" per hour, or "IT'S GOOD KITE FLYING WEATHER" when the average wind speed exceeds a certain threshold.

As with many such devices, data can be displayed in either english or metric units. Unlike some competing units, each category of data element can be displayed in english or metric units independently. For example, temperature can be displayed in celsius while barometric pressure is displayed in inches of mercury. Several data elements have more options. Temperature can be displayed in Farenheit or Celsius in either whole units or to the tenth of a degree. Wind speed can be displayed in MPH, knots, KMH, or meters per second. Barometric pressure can be displayed in inches of mercury, millibars, hectoPascals, or millimeters. (Though hPa and mb are identical, the choice of units is displayed on screen - depending on one's choice of units, the display will read either "1004.3 mb" or 1004.3 hPa. Rather a nice touch.) Knots, KMH, and m/s display to the tenth unit, while MPH displays in whole units (which is contradicted by much of Davis' own advertising materials and the owners manual itself).

Like most new high-tech products, the VP has indeed had its share of problems. Several owners posting on the bulletin board (including me) have experienced defective humidity sensors, where the sensor reads 100% humidity at some point then rarely drops below the high 80's regardless of actual conditions. Davis has been good about shipping out replacement parts, then having the owner return the defective unit. Some users have complained about the contrast on the console; I personally have never found this to be an issue. The original units were designed, according to Davis, to save memory and battery power by omitting several wind speeds, such as 4, 9, 15, and 23 MPH. This seems a foolish tradeoff, and units developed after mid-October 2001 have reportedly had this corrected. Several users, including this one, have also experienced a "faded" area in the LCD screen near the indoor temperature display. Perhaps the most common complaint, applicable only to the wireless unit, is of numerous missed transmissions and lost data. Davis opted to use 916.5 MHz for their "DavisTalk" system, rather than 433 MHz as used by most other weather stations. This was a very poor choice in my opinion; 916 MHz is very close to cordless phones, and my own station experiences serious interference from my own cordless phone. Quite a few users have opted to add a wireless repeater to their systems to optimize reception - all who have done so and posted results are very pleased with the results - but this is a rather expensive solution for a typical installation. An equally bad decision was to not equip the console with flash RAM, to allow users to download upgrades over the internet. Davis has used the new wind chill formula in units programmed after mid-October 2001, has reportedly corrected the "missing" wind speeds, and made several other fixes to their firmware, but to benefit from these changes, a user must part with his unit for several weeks (and $35) to have the firmware upgraded. Should the console be defective, Davis will repair or replace it and install the latest firmware, but unless there is a defect, the user must pay for the firmware upgrade, and more importantly, be without the station for some weeks. For me, one of the more annoying decisions Davis made was to use and display a 10-minute average wind speed rather than a lesser and more common period, such as the METAR/WMO standard of 2 minutes. Use of a 10-minute average artifically reduces the "real" average wind speed.

Lest the reader think the negatives outweigh the positives, let's look at some of the groundbreaking features of the VP. The console display is among the best available at any price. The display shows most important data all at once, obviating the need to scroll or page between displays. Most items on the screen can be changed among set choices, but a lot of data is available at any given time. I might have configured the screen a bit differently in terms of the choices, but that's an individual matter. The console has impressive graphing and memory capabilities. While too extensive to describe here, for most variables there are multiple sets of data available in 24-unit chunks. For example, the high wind speed can be viewed on the graph for the last 24 10-minute periods, the last 24 hours, the last 24 days, the last 24 months, or the last 24 years!