count up or down faster. The meter offset will return to factory reset when power is turned off. You can change the
factory reset by removing the 4 screws in back and taking off the front cover. Turn the small round potentiometer below
(nearest the battery) that says “internal offset”.
Measurements:
This type of meter is often used to check residual (accidental) magnetization of parts. In general, this accidental
magnetization is
perpendicular
to the surface of the part, so the probe can be placed flat against the part, and this is the
correct direction for detection of that field. You may need to scan the probe across the surface to find the highest
number. This highest reading is usually found at the ends or sharpest points of the part.
There are some peculiarities of measuring residual magnetization. Long, thin steel parts will often “amplify” the Earth field
by a factor of 10 or so, at the ends of the part. If the long-axis of the part is pointed east-west, or perpendicular to the local
indoor field, this is not a problem. The strength of the Earth field is about 0.5 gauss, so you may see up to about +/-5
gauss at the end of a properly
demagnetized
steel rod if the rod is pointed in the direction of the Earth field. The north pole
of the earth is not horizontal in most locations. In most of Asia the magnetic field direction
is
within about +/-20° of
horizontal. In North America if you face north and then look downward from horizontal 20° (Central Mexico) to 55°
(Northern US) to as much as 90° down in parts of Canada,
that
is the direction of magnetic north. You can detect the field
strength and direction with the meter. Note that with the bulge in the probe pointing toward the Earth north, you will read a
negative number, because it's pointing toward the
south
pole of a magnet. If you flip the sensor 180° so that the bulge is
facing Earth north, you will read a positive number.
When scanning the surface of parts, if you want to measure with a resolution of less than five gauss, it’s recommended
that you keep the probe end stationary with its thin axis (magnetic sensitivity direction) pointed perpendicular to the local
magnetic field direction, and with OFFSET adjusted so the display instantly reads zero. You’ll know it’s correctly zeroed
and perpendicular to the local field direction if when you flip the probe end 180°, the display continues to read zero. Then
scan the part along the flat surface of the probe and look for the highest number (either positive or negative).
SPECIFICATIONS: 1-axis DC Gaussmeter GM1-HS
Range/Resolution:
799.99 G/0.01 G; with polarity indicator
Accuracy:
+/- 1% of reading (16° to 29°C); +/- 2% (-4° to 65°C)
Offset:
Auto Zero. Also fine offset (0.01 gauss resolution)
Probe (non-detachable):
2.1 (thick) x 4.3 x 24 mm
Size:
5.2 x 3.6 x 1.6 inches; 132 x 91 x 41 mm
Weight:
8 oz
Battery:
9 volt alkaline (~ 20 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
