Elcometer 550 Operating Instructions Manual page 11

2.5.3 Taking a reading
Once the gauge has been zeroed, start by placing the gun in roughly the correct position. Highlight
"measure" on the main screen and then press either the menu button on the gauge or the go button on the
handle. The measurement screen will then be displayed.
The instrument requires several echoes in order to return a
result. Echoes are only recorded when the signal is strong
enough and the sensor gun is the correct distance from the
substrate. The number of echoes taken is displayed. For a
measurement to be calculated at least 5 echos are required.
For increased accuracy more echoes may be taken.
When the desired number of echoes has been received,
pressing the Go button on the sensor gun or the Menu button
on the gauge, prompts the gauge to calculate the coating
thickness.
2.5.4 Error Codes
1 The thickness measured was above the high limit
4 The thickness measured was below the low limit
10 Echoes varying (can occur if probe moved and measured several different thicknesses)
20 Too few echoes received for calculation
255 No echoes found
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