Barographs
German

download the leaflet: 113-0E Barographs
                                        
113-1E Microbarograph

Overview:


No.


78a
78b
78m


Designation


Normal Barograph
Large Barograph
Micro-Barograph

range in
hPa


105
105
66*

 Recording
height in mm
for 1 hPa


0.75
1.5
3.8

Accuracy of reading / limits of Error

 ± 0.3 hPa
± 0.2 hPa
± 0.1 hPa











* If occasionally occurs extrema of pressure variation the customer can use the a device to select the suitable  range of 66 hPa (mbar) within the total range of 146 hPa (mbar)

All types are availlable in wooden and metal casings.

The aneroid barographs are precision instruments for continuos recording of atmospheric pressure.
 
In comparison with the values of atmospheric pressure read on mercury barometers, those obtained by aneroids are independent of the resp. ambient temperature and gravitational acceleration so that the corrections customary with mercury barometers are not applicable.
Thus, aneroid-barographs are used everywhere, where there's quick determination of momentary atmospheric pressure of interest, in connection with observation and documentation of barometric pressure.

As mean atmospheric pressure decreases with increasing height, barographs must always be adjusted to the height of the place of mounting. They, thus, are adjusted to certain ranges of height, at which they may be used only then.

In order to make possible a far-reaching range of utility for each instrument, the barographs named hereafter are so designed that they may be adjusted to several (4 ... 6) measuring ranges, without readjustment. To this end the connection band between transmitting axles is provided with figure-bearing holes for the coupling pin. A worded plate on the ground plate indicates the number of the hole for each local height, as well as the corresponding chart. 

No. 78a Normal Barograph

This Barograph 78a is the preferently used type in national and foreign weather stations and in other places of climatological interest. It registers atmospheric pressure at a height of recording of 0.75 mm for 1 hPa; the limits of error amount to ± 0.3 hPa.
 
78a - NormalbarographIn standard execution the instrument is supplied in a metal casing, which has been provided with a very resistant grey hammertone finish. If the barographs named are to be installed in a representative locality, where the metal casing does not correspond to the frame of the equipment, they may be supplied with an all-around glazed
rare-wood casing.

With high quality set of eight aneroid boxes as well as complete temperature compensation in the total pressure measuring range.

Time of drum rotation:
     a) daily        or
     b) weekly     or
     c) reversible clockwork from daily to weekly

78a NormalbarographRange: 105 hPa (mbar)

Recording drum:
     Ø 93.3 mm, height: 93 mm
     time of running: app. 9 days
     Recording height for 1 hPa: 0.75 mm
     Recording height total: 79mm

Dimensions: 290 x 125 x 205mm
Gross weight: 4.7 kg

Accessories:
     1 spare fibre pen
     1 set of recording charts
      (100 charts for daily rotation or 54 charts for weekly rotation)

This instrument is manufactured in four types, which distinguish each other solely by the local
heights at which they may be used:

No. 78a
for local heights from -50 to +1350 m, referring to sea level, 
adjustable to 6 measuring ranges, 105hPa each, between 825 and 1060 hPa

No. 78a2
for local heights from 1350 to 3000 m above sea level, 
adjustable to 6 measuring ranges, 105hPa each, between 655 and 900 hPa

No. 78a3

for local heights from 3000 to 4300 m above sea level, 
adjustable to 4 measuring ranges, 105hPa each, between 555 and 740 hPa

No. 78a4
for local heights  from 4300 to 5700 m above sea level, 
adjustable to 4 measuring ranges, 105hPa each, between 445 and 630 hPa


No. 78b Large Barograph 78B - Large Barograph

This barograph for precision-measurement, as compared to the normal barograph 78a, has the double scale of recording. A corresponding larger number of aneroid-boxes (12 pieces) guarantees measuring accuracy for recording height of 1.5 mm for 1 hPa; the limits of error amount to ±0.2 hPa.

Adjustment of 6 partial measuring ranges of 105 hPa each without readjustment.

The large barograph is supplied in casing of rare wood (model 78b) or with metal housing (model 78bm) and manufactured in 3 types, which differ in local heights only.

No. 78b resp. 78bm
for local heights from -50 to +725 m, referred to sea level, 
adjustable to 6 measuring ranges, 105hPa each, between 885 and 1060 hPa

No. 78b2 resp. 78bm2
for local heights from 700 to 1850 m above sea level, 
adjustable to 6 measuring ranges, 105hPa each, between 765 and 970 hPa

No. 78b3 resp. 78bm3
for local heights from 1800 to 2700 m above sea level, 
adjustable to 4 measuring ranges above, 105hPa each, between 885 and 850 hPa

Time of drum rotation:
     a) daily        or
     b) weekly     or
     c) reversible clockwork from daily to weekly

Range: each 105 hPa (mbar)

Recording drum:
     Ø 133 mm, height: 174 mm
     Recording height for 1 hPa: 1.5 mm
     Recording height total: 160mm   
     time of running: app. 9 days

Dimensions of casing of 78b: 400 x 190 x 300 mm
Gross weight of 78b: 8.2 kg

Accessories:
     1 spare fibre pen
     1 set of recording charts
       (100 charts for daily rotation or 54 charts for weekly rotation).

No. 78m Microbarograph

The Microbarograph 78m is a highly sensitive measuring instrument for especially sensible and precise recording of atmospheric pressure. Owing to the great height of pen travel of 3.8 mm, for every hPa (mbar) of alteration in pressure, also slightest variations of pressure and fine structurees are well to be made out and read with a accuracy of ± 0.1 hPa (mbar).

As model 78m the measuring system is mounted on a solid light-metal socle, on which the glazed protective fine wood casing is resting. The microbarograph model 78mm has a metal housing.

The set of aneroid cells consists of fifteen single cells which, to a high degree, are free from ageing and hysteresis, because best-suited materials are chosen, only, and owing to a special thermic treatment. Frictional resistances of the transmitting system has been reduced to a minimum by most careful manufacture of the bearing beds and by arranging the aneroid cells ina hanging kind of way. A small, electro-magnetically actuating vibrator generates a slight, hardly sensible vibration of the housing and the measuring system, which contributes to a further reduction in bearing friction, and to an increase in accuracy and sensibility of pen adjustment.
The aneroid cells are protected against dust and damage by a metal tube.

The Microbarograph 78m is supplied in 12 types for different site of installation between -1200 and +4600 meters. Seven ranges of 66 hPa each one displaced from the following by 13.3 hPa, may be covered without new calibration, so that the total range comprices 146 hPa. The  adjustment  of  the  seven  ranges  for  the  place  of  installation  is  effected  in  a  way,  which is as quick and easy, as it is sensitive, by turning the setting screw arranged above the set of aneroid cells which is equipped with a correspondingly numbered, divisioned disc arrangement. If  occasionally  occurs  extrema  of  pressure  variation  the  customer  can  use  the  above  described device to select the suitable range of 66 hPa (mbar) within the total range of 146 hPa (mbar).

Version



78m03
78m02
78m01
78m 1
78m 2
78m 3
78m 4
78m 5
78m 6
78m 7
78m 8
78m 9

Height above
sealevel in m


1200...- 650
-750...- 200
-450...+100
0...+600
+350...+950
+800...+1450
+1150...+1800
+1650...+2350
+2100...+2800
+2650...+3400
+3100...+3900
+3700...+4600

Range adjustable
between
hPa (mbar)

1052...1198
1002...1148
962...1108
907...1053
867...1013
812...958
772...918
722...868
682...828
627...773
587...733
532...678




















78M - MikrobarographTime of drum rotation: 1 week or 1 day
                 reversible by exchange of gear wheel (optionaly)

Range: 66 hPa (mbar), adjustable within 146 hPa (mbar)
Recording drum:
     Ø 133 mm, height 259 mm
     height of recording: 247.5 mm (1.33 hPa (mbar) = 5 mm)
     time of running: app. 9 days
Chart size: 261 x 428 mm (h x w)
Dimensions of casing of 78m: 450 x 230 x 385 mm
Weight of 78m: 10.5 kg

Accessories:  
     1 set of charts
        (54 sheets for weekly or 100 sheets for daily rotation)
     1 spare metal pen and 1 bottle of special ink
        or alternative 1 fibre pen
     1 power supply for vibrator

When ordering, please indicate altitude of site of installation, selected drum rotation and type of housing


Dr. Alfred Müller - Meteorologische Instrumente KG
Chausseestraße 39 / 42c, D-15712 Königs Wusterhausen
Telefon: +49 (0)3375 9025-32 Telefax.: +49 (0)3375 9025-36
e-Mail: dr.a.mueller-r.fuess@t-online.de