5
Changing the factory-set offsets:
This operation would never normally need to be done, however if the factory
offsets have been accidentally changed (by accidentally doing the steps listed below), you can restore them to the
correct values, which will remain in non-volatile memory (stored even if the battery is removed for a long time). Make
sure that you have first adjusted the offsets to zero properly, as described above. Then push downward on the
OFFSET knob so a triangle appears over “Offset Adjust”. Release the knob and then press and hold down the
“Alarm Set” button until the display blinks. While still pressing “Alarm Set”, press and release “Data Option”. The
offsets at that moment will be stored (this will not change the present offsets).
Subtracting out the ambient (background) field:
In some situations, the change in the field (from its ambient
value) is the variable that needs to be measured. If that is the case, place the probe in the ambient field
in the
orientation in which it will be used
and press “Reset” (knob must be on “Measure”, while displaying “Magnitude”).
This will subtract the ambient field from X,Y,Z so that all variables will read zero (within a few counts). Then any
displayed values (including peak hold values) will be with respect to the ambient field. Generally the ambient field
present is just the Earth field (typically 1/2 gauss), but any field up to 799 gauss in any direction can be subtracted
this way.
Be careful about the meaning of “subtraction” here. An example will clarify this. Suppose the probe is oriented so that
X is facing up, Y is facing east and Z is facing north, and that the ambient field is X = 10.00 gauss and Y and Z are
each 0.00 gauss. Then the magnitude is also 10.00 gauss. Press “Reset”; this produces no change in the Y or Z
offsets (which are already zero) but this action causes 10 gauss to be subtracted from whatever X reads from that
moment on, so X will read zero, and thus the magnitude will also read zero. If the actual field is now reversed so that
the vertical component becomes -10.00 gauss (as opposed of its former value of +10.00), then of course Y and Z will
continue to read zero. However, now X will read “-20.00” and magnitude will read “20.00”, even though the true
magnitude remains 10.00 gauss (magnitude has not actually changed). In general, if an offset reset is done, the
magnitude will initially read zero, but it will increase if the field direction changes (or if the probe is reoriented).
SPECIFICATIONS: 3-axis DC Gaussmeter VGM
Range/Resolution:
0-799.99 G/ 0.01 G. Includes polarity of X, Y, Z. Magnitude = is sqrt of sum of
squares.
Accuracy:
1° of reading (16° to 29° C), 2% of reading (-4° to 65° C) Pointing accuracy 1%
of arc.
Offsets:
Relative zero (subtracts present field from X, Y, Z);Unlimited manual offset of X,
Y, Z.
Probe:
3-axis non-detachable 6.3 x 6.3 x 50 mm long. All three sensors are within 1.5
mm of probe end.
Peak Hold:
0.005 sec time constant. Peaks in X, Y, Z and magnitude are recorded and
stored separately.
Alarm:
Associated with magnitude only, 5 millisecond response time; Simultaneous red
light.
Alarm Levels:
100 levels can be selected, from 1.00 to 790.00 G
Meter Size:
5.8 x 3.8 x 2.0 inches; 147 x 97 x 51 mm
Weight:
11.7 oz
Battery:
9 volt alkaline (~ 10 hour life) / "Low Battery" indicator.
The warranty period for this meter is one year from the date of delivery.
Manufactured in the USA by AlphaLab, Inc. 3005 South 300 West Salt Lake City, Utah 84115 USA www.trifield.com - [email protected] - (801)487-9492
