The microbarograph is a precision measuring device for recording atmospheric pressure. The altitude is set using a knob at the measuring location. Recording is performed on a drum clockwork with a hand-spring winding mechanism in accordance with DIN 8300 and DIN 58658.
The movements of the aneroid capsule set are mechanically transmitted to the recording arm via a lever system, with an interposed bimetallic system ensuring perfect temperature compensation across the entire measuring range. The capsule set consists of 15 individual capsules, which are largely free from aging and elastic after-effects thanks to the selection of the most suitable materials and special thermal treatment. The frictional resistance of the transmission system is reduced to a minimum. An electromagnetic vibrator, powered by 6...8 VDC from a small transformer, generates vibration in the frame and measuring mechanism, which contributes to further reducing bearing friction and increasing the accuracy and sensitivity of the recording nib adjustment. The measuring mechanism is mounted on a robust light metal base, onto which the glass-enclosed mahogany protective case sits. The capsules are protected against damage and dirt by a metal tube. The reading can be corrected using the zero-adjusting screw, for example, by comparison with a reference barometer. By pressing the push button on the right side of the base, time markers can be applied in the form of short deflections of the pen. With the selected altitude scale for recording (1 torr = 5 mm) and a recording height of 250 mm, the measuring range that can be recorded in one go is 66 torr. The barograph is available in 12 models for 12 consecutive altitude ranges of the installation site between -1200 and 4600 m. Within each of these
12 ranges, seven measuring ranges can be set without readjustment, each 10 Torr apart, so that the total measuring range covers 110 Torr. This adjustment is carried out conveniently, quickly, and sensitively by turning the adjusting screw located above the set of sockets, which is equipped with a correspondingly numbered dial arrangement for this purpose.
The device also serves to detect occasional exceptional peaks that exceed the measurement range of 50 Torr. The recording drum is equipped with a switchable clock mechanism; by operating a switch, the rotation period can be selected as desired, either 1 day or 1 week, without replacing the transmission wheels.
The device has the following functions:
- network-independent and tamper-proof
- wider recording drum (160 mm)
- Pressure measuring device with overload protection for transport up to 4600 m altitude
- 2-fold can set
- corrosion-resistant, elastic material
- good measurement accuracy (± 0.1 hPa)
- long-term stable
- temperature compensated
- switchable (1d - 7d) mechanical movement
- high reliability
- maintenance-free