The Meteograf Precise Electronic Marine Barograph shares the advantages of both mechanical and electronic instruments.

Interested in the Weather?

The Meteograf is a precise electronic barograph designed for the observation and recording of climatic pressure changes, which are important indicators of forthcoming wind and weather conditions. The instantaneous air pressure shown on a conventional barometer gives only vague information about imminent weather changes. Only by exactly recording the current air pressure and the rate at which it is rising or falling is it possible to make reliable short-term weather predictions and to give prompt warning of dangerous weather conditions.

Modern Concept

Using the most modern technology (microprocessor, surface-mounted electronics, etc.), the Meteograf combines the advantages of traditional mechanical barographs with those of purely electronic instruments and also boasts small dimensions, low weight and high precision plus ease of operation, good readability and the requirement to reload the recording paper roll only once per year. Attractive new functions, such as Zoom, Transport and Time Change (see below) are also offered for the first time in a unit of this size and price range.

High Accuracy

A microprocessor controls all the functions of the Meteograf. An analogue signal from the internal pressure sensor is amplified in a signal processor, digitalised and input to the microprocessor, which calculates and outputs the air pressure. Linearity and temperature correction factors for the pressure sensor are pre-programmed into the microprocessor, making the installation of trim potentiometers unnecessary and guaranteeing extremely high accuracy over the whole operating temperature and pressure range, as well as optimal long-term stability without positioning or hysteresis errors.

Easy Set-Up

To set up the Meteograf, the current air pressure is entered using the push buttons next to the display. If the current air pressure is not known, the local elevation is entered instead. The Meteograf then automatically converts this to the equivalent air pressure, as defined in the ICAO Standard Atmosphere.

Large Operating Range

The Meteograf can be used at any altitude between -500 and 6,000 m above sea level (-1,600 to 20,000 ft). Air pressure in the range 960-1055 mBar (28.3-31.2 inHg), reduced to sea level, will be displayed and recorded.

4-Day Display: Rectilinear and Ink-free

The scriber point engraves the barogram into the reverse side of the waxed paper roll. The pressure record from the previous 4 days is shown clearly in the main display window. The continuous rectilinear record (unlike the circular barograms of many barographs) is therefore produced without pens (so no dirtying of the fingers or of the apparatus itself and no need to replace pens). The scriber is behind the paper so a new paper roll can be easily loaded and tne paper roll is sufficient for 1 year’s operation.

Precision Movement

The paper movement is controlled to extremely high tolerances by a small servo motor. A second servo motor controls the movement of the scriber via a spindle.

Numerical Display

In addition to the linear display in the main window, the Meteograf has a numerical LCD display which normally shows the current air pressure, but is also used to select and adjust the Meteograf’s operating functions.

Zoom Function

The LCD can be used to observe short-term pressure changes which would be indiscernible on the main display. Together with the current air pressure, the overall change in air pressure (±0.1 mBar) in the last 1, 5, 15, 30 or 60 minutes may be displayed. This enables a uniquely accurate observation of the approaching weather.

High Waves? No Problem!

An electronic filter cancels out fluctuations in indicated air pressure caused by operation in rough water.

Storm Warning

Weather conditions, particularly wind strength, are dependent on the rate at which air pressure changes. For any given geographical position, a given rate of change of air pressure may be defined as indicating an imminent storm. To provide prompt warning of this, the Meteograf has an optional aural alarm as well as a visual alarm, which is activated when the rate of change of atmospheric air pressure exceeds a preset limit. This limit is adjusted by the operator to suit the perceived danger level.

Transport Mode

Transporting the Meteograf usually results in a change in altitude, producing a change in air pressure unrelated to any meteorological effects. When in Transport mode, the Meteograf ignores these changes and displays the current altitude on its LCD display. When the relocation is complete, the Meteograf can be easily reset to its normal Display mode. An overall correction to the display can then be made to account for any weather-related pressure changes whilst the device was in Transport mode.

Completely Independent

To reduce power consumption. the microprocessor is automatically switched to an energy-saving mode between measurements, with only the LCD display and other basic functions operating continuously. The total power consumption is so low that the Meteograf will run off a single household battery for about 12 months. There is no requirement for any connection to an external power source.

Other Details

The battery voltage is continuously monitored, the LCD display indicating battery capacity as one of four levels; Charge sufficient, Charge low, Battery change required and Battery flat.

To ensure maximum reliability and durability when operated at sea, or in any hostile environment, the Meteograf uses high-quality gold-plated electrical contacts throughout. For battery connections, these are duplicated. The electronic parts are lacquered for protection against corrosion. The mechanical parts are manufactured from stainless steel and all other parts are high quality plastic.

PC Interface

The Meteograf is also available with a PC interface if required. The Meteograf contains a memory in which the barometric pressure data recorded over the last 10 days is stored. The data is recorded to a tolerance of 0.1 hP (equivalent to 0.1 mBar). Using the data transfer cable supplied, this data can be downloaded to a PC for permanent storage or for further manipulation. The software is compatible with Microsoft Windows Versions 95, 98, NT 2000 and XP. Using the Excel program, the data downloaded can be automatically displayed graphically using a Macro function. As this software is freely available, it can be customised by the operator to suit his or her individual data processing requirement.

Technical Data