Troubleshooting - Greenlee SF-780 Manual De Instrucciones

Prescanning the Target Area
Notes:
• Before scanning, wipe the area to be scanned clean of sand and pebbles. If
the scanning surface is fairly rough, place a thin piece of cardboard between
the surface and the unit. The thickness of the cardboard must be subtracted
from the depth reading to determine the actual depth to the target when using
this procedure.
• This tool is designed to operate at approximately 21 ° C (70 ° F). Sensitivity
decreases slightly at higher temperatures, but is not noticeably affected at
lower temperatures.
1. Turn on the unit away from the surface to be scanned.
2. Place the unit on the scanning surface and move from side to side. As a
target is approached, an increasing number of depth bars will show. At the
point closest to metal, the plus sign will change to a minus sign and there
will be a beep (in AUDIBLE mode).
3. The type of metal detected will be indicated by the magnetic/nonmagnetic
icon.
4. Once you have located a target, reposition the SF-780 over it and scan
perpendicular to your original scanning direction to be sure you have
determined the extent of the target. If the target is a rod or pipe, the depth
indicator will remain constant as you scan along the length.
5. Continue scanning to determine if there are multiple targets. If precise depth
is important, determine an area that is free of metal for recalibration (refer to
next section).
6. If desired, mark target locations. Crosshairs on the top and front of the unit
show where sensitivity is maximum.
Recalibrating for Maximum Depth Accuracy
The SF-780 automatically calibrates at turn on. However, depth accuracy is
dependent on the materials in the vicinity of the measurement, in particular,
when the materials may contain metal or metallic minerals, as is common with
various mixes of concrete. Thus, it is often beneficial to recalibrate after
prescanning targets before making a final determination of depth. Recalibration
will not affect the positioning accuracy.

Troubleshooting

Situation
Difficulty detecting metal
accurately.
Inaccurate calibration and/or
depth reading because magnetic/
nonmagnetic objects positioned
side-by-side or on top of each
other.
Calibration is lost.
Beep doesn't seem relative to
targets.
Unit makes long, low-pitched
tone and display does not return
to normal.
Low battery indicator.
Greenlee / A Textron Company
Probable Causes
Metal spaced too closely together prevents
calibration.
• Calibrated directly over a metal target.
• Concrete and rebar are in segments that could
have been poured at different times.
Unit was turned off or mode changed.
• Scanning near the edge of a piece of concrete.
• Target is more than 10 cm (4") deep; unit will
not beep at the same time as plus/minus
change and maximum depth bars appear.
Calibration error has occurred.
Battery has less than 5 hours of use remaining.
To recalibrate:
1. Locate an area on the surface where there is no indication of metal.
Note: If a grid pattern exists, such as may occur with rebar in concrete, there
may be no area free of metal. In this case, best results may be obtained by
calibrating midway between targets. However, accuracy may be affected and
recalibration may not improve overall depth accuracy.
2. Press and release the PRESS TO RECALIBRATE switch. All icons on the
display will light momentarily during calibration.
3. Rescan target areas. A final determination of depth can now be obtained
form the depth indicator.
Depth Accuracy and Target Size
The depth readings are specifically tuned for measuring 1/2" copper pipe or #4
rebar. For any other metal object, the depth reading of the SF-780 will be less
accurate.
• Small objects such as nail heads will be shallower than indicated.
• For rebar other than #4, the depth reading is accurate to about ± 2.54 cm
(± 1").
• For 1/4" copper pipe, actual depth will be about 30% shallower than indicated.
• For 3/4" copper pipe, actual depth may be about 20% deeper than indicated.
• Large metallic objects, such as pieces of sheet metal, at very shallow depths
may give erroneous indications of metal type (magnetic vs. nonmagnetic).
Specifications
Battery Type: 9 V alkaline
Position Accuracy: Center of #4 (1/2") rebar or 13 mm (1/2") copper pipe at a
minimum grid spaciong of 152 mm (6"), typically within 13 mm (1/2")
Depth: Up to 152 mm ± 25 mm (6" ± 1")
Operating Temperature: –7 °C to 49 °C (20 °F to 120 °F)
Storage Temperature: –29 °C to 66 °C (–20 °F to 150 °F)
Humidity: 80% RH (noncondensing)
Note: Sensing depth and accuracy can vary due to moisture content of
materials, wall texture, and paint.
Solutions
• Avoid wearing any jewelry, including watches, when using this tool and
move large metal tools away from target, when feasible.
• Use constant, light pressure during scan.
• Allow 5 to 10 minutes for temperature to stabilize before operating if
unit has been moved to an area with a –12 °C (10°F) change or greater
(e.g., from air-conditioned building to outdoors on a warm day).
• Calibrate away from metal to accurately determine depths. Move the
unit over a few inches and recalibrate.
• Make sure the tool touches the surface it is scanning.
• Do not rely on single calibration for the entire area. Prescan each
segment separately; calibrate and determine depth of targets for each
segment of concrete.
• For maximum accuracy on concrete, make sure concrete is fully cured.
Recalibrate every time you change mode or turn on unit.
Ignore beep and rely on depth bars to locate object.
Reposition the SF-780 and recalibrate.
Replace battery to maintain sensitivity.
3
4455 Boeing Dr. • Rockford, IL 61109-2988 USA • 815-397-7070
SF-780