Gigahertz Solutions NFA 1000 Operating Manual page 16

The NFA guides the user through the nine points by means of short audio signals
("beeps"). These nine points shall always be processed in the same order, head ar-
ea: left, middle, right, followed by torso area: left, middle, right and finally feet area:
left, middle, right.
 The beeps are not time controlled but the NFA will adjust itself to your personal
work rhythm by "sensing" whether it is being moved or it is lying still
you can finish the nine point measurement within less than a minute or – if you
prefer to take it a bit slower – you need not let yourself "be rushed through the
measurement by the beeps".
 The algorithm is as follows: after the activation (see above) the NFA "waits pa-
tiently" to be moved (... that is being moved to the first measurement position:
top left) and it will not beep to confirm the next measurement before the instru-
ment has been left still in that position for a couple of seconds
pick up a valid measurement). After the beep – and in your speed – you can pro-
ceed to the next measurement position
 PLEASE NOTE: In order to support this algorithm move the NFA more or less
rapidly from one measurement position to the next, and "bump" it onto the bed's
surface with a little impact in order to give the transition movement a clear end
 For an analysis of the collected data use NFAsoft.
5.3 Guided 6-Point-Measurement
of Working Places
The NFA and the NFAsoft also support the measurement of
working places. In this case six measuring positions are to be
collected, as shown in the drawing. For a selection of the work-
ing place measurement on the NFA keep the "Mode" button
pressed until "6Pt" is displayed on the LCD. For the further pro-
cedure follow the instructions of the 9-Point-Measurement in the
order: head, elbow, bottom, hands, knees, feet.
5.4 Long Term Data Logging
The normal approach in building biology is to record only the AC magnetic field, and
this as tRMS. Why only the magnetic field? Only AC Magnetic Fields are subject to
large fluctuations, as they depend on the actual current flow which is variable. The
interval for recording data is set to 10 data sets/sec.
9
The interval from beep to beep can vary between 3 and up to 20 seconds according to your work rhythm and
movement pattern.
10 This time delay is user-definable with NFAsoft.
11 After the beep the NFA will wait up to 20 seconds for a movement
12 This way the NFA can distinguish more reliably whether it is in motion or kept still. If you use the potential-free
rod PM4s then try not to move the instrument after you have "hit" the measurement point, if you use a holder
then withdraw quickly to a minimum distance of 1.5 m and keep still there in order to avoid movement-induced
"pseudo-fields".
350-027_NFA1000400-6-2_EN-von-susanne as of October 2011
11
.
- 16 -
9
. This way
10 (... in order to
12 .
© Gigahertz Solutions GmbH