Engineering mode is entered by holding down the ENTER button while turning on
the power. The Engineering mode displays
“
En
”
(for Engineering) for two sec-
onds when the button is released. When the two seconds is up, the Magnetic
variation is shown in degrees. The present set-up is shown as
“
MAG.
”
(for mag-
netic readings) or
“
TRUE
”
(for true readings). Note that the magnetic variation
affects only true readings, and need not be corrected as described below if mag-
netic bearing readings are required.
Any of the following settings can be done when in Engineering. If more than one
different setting is to be done, it is necessary only to return via the
“
En
”
display
between different adjustments or settings, as described below.
ADJUSTING MAGNETIC VARIATION
The Earth
’
s magnetic variation varies from year to year, and from place to place.
The appropriate variation value can be found by reference to Almanacs, maps, or
charts. The variation is the offset of magnetic North from true North. If the
Magnetic North (the variation) is West of true North, enter it as a positive number.
Conversely, if it is quoted as East of true North, enter a negative variation value.
If not already in Engineering (
“
En
”
displayed), hold down the ENTER button while
turning on the power to put the unit into the Engineering mode. The display
shows
“
En
”
(for Engineering) for two seconds. The display then changes as
shown in Figure 6 to show the stored magnetic variation and whether the unit is
operating in Magnetic or true modes (Figure 6 shows Magnetic operation, and an
Eastward variation of 6.3
°
).
FIGURE 6 - Magnetic Variation Display
Positive numbers represent Westward variations, and negative numbers (as
shown on Figure 6) represent Eastward variations. Each press of up
or down
alters the stored variation in steps of 0.1
°
. If the total variation is greater than ±
9.9
°
, the fractional part of the angle is altered, but cannot be shown.
