Bartington Mag-01H, Operation Manual

BARTINGTON INSTRUMENTS

Page 19 of 32 OM2020/5

Figure 7  Example of likely position of circle graduation lines.

3.  To achieve a correct reading, turn the micrometer screw to align the circle graduation line 

exactly in the middle of the double line index (see Figure 8 below).

Figure 8. Circle graduation line aligned exactly in middle of double line index.

4.  Example: 

The vertical measurement displayed in Figure 8 is approximately 272°52’44’’.

Note: 

For further information refer to the 

Wild T1 manual

, section 4.5.

6.5. Performing Observation of Declination

Connect the probe cable to the magnetometer and switch on the instrument. Prior to 
commencing measurements, decide which sensitivity setting can be used. Attempt a trial null 
measurement on x10 sensitivity (0.1nT resolution). If noise exceeds 0.5nT p-p then x1 sensitivity 
setting should be used. This is recommended for most observations.

Note: 

Before taking readings on the Mag-01H, ensure that the offset control is set to zero 

and the toggle switch is in a central position.

Note:

 A small offset error (a few nT) will be present when switching between the x1 and 

x10 sensitivity settings. This in no way affects observation accuracy provided that the 
sensitivity setting is not changed during any set of four measurements per observation. If 
the audio null indicator is fitted, select an appropriate volume setting using the turn button 
fitted on top of the Mag-01H.

For this observation a reference target with a known azimuth (TA) is required. This is the angle 
subtended between the target and the Geographical Meridian (GM) at the point of observation. 
The target azimuth can be surveyed using GPS measurements.

The setting of the horizontal circle will be arbitrary; therefore, the target datum (TD) reading 
must be recorded first. With the circles unclamped, roughly align the telescope with the target 

Micrometer  
Scale