Velleman CS130 Bedienungsanleitung Seite 4

5 . Over view
Refer t o t he illust rat ions on page 2 of t his m anual.
m e t a l d e t e ct or
A arm rest
B handle wit h t race but t on
C cont r ol box
D bat t ery com part m ent
con t r ol b ox + in dica t or
1 LOW BAT
2 VOLUME
3 TUNE
4
5 DI SC
6 analogue m et er
6 . H ow it w or k s
•
A ( low fr equency) m et al det ect or basically consist s of a t ransm it t er, a r eceiver and a
m icropr ocessor ( cont rol box) which handles t he signals.
Tr a n sm it t e r
•
The t ransm it t er is a coil of wire locat ed inside t he sear ch coil. By sending an alt ernat ing current
t hrough t his coil a m agnet ic field is generat ed, having a polarit y point ing eit her int o or out of t he
ground. This m agnet ic field will induce a flow of curr ent inside nearby m et allic obj ect s. These
obj ect s in t urn will creat e a m agnet ic field wit h a polarit y which is usually opposit e t o t hat of t he
m agnet ic field of t he t ransm it t er.
Re ce ive r
•
The receiver is anot her coil of wire t hat is locat ed inside t he search coil and which is const ruct ed
in such a way t hat t he m agnet ic field of t he t ransm it t ing coil does not induce cur r ent in it .
Magnet ic fields from nearby m et allic obj ect s howev er will produce an elect ric curr ent in t he
receiver coil.
Ph a se sh ift
•
The signal received fr om t he r eceiving coil will usually be delayed v er sus t he t ransm it t ed signal
due t o t he t endency of conduct ors t o im pede changes in t he flow of curr ent , t he so called
induct ance. The delay is r efer red t o as p h a se sh ift . Met al obj ect s t hat are prim arily induct ive
e.g. large t hick obj ect s m ade of good conduct or s ( gold, silver, copper...) will result in large phase
shift s, wher eas m et al obj ect s t hat are prim arily r esist ive e.g. sm aller t hin obj ect s m ade of less
conduct ive m at erials will result only in m inor phase shift s. Refer t o t he t able below for a short
ov erview of t he elect rical conduct ivit y of som e m at erials.
M a t e r ia l
silver
copper
gold
alum inium
calcium
zinc
•
Not e t hat det ect ion also depends on t he size, shape, dept h... of t he m et al.
Fe r r om a gne t ic
•
Subst ances t hat usually conduct very poorly or not at all can becom e m agnet ized when inside a
m agnet ic field, result ing in a st rong signal picked up by t he receiver. Howev er , t his signal shows
lit t le or no phase shift . Soils cont aining sm all grains of iron- bearing m inerals will show
ferr om agnet ic charact er ist ics.
10/ 10/ 2014
low bat t ery indicat ion: light s up when v olt age dr ops below 8.8V
volum e but t on: set speaker or headphone v olum e t o norm al or low
" ground balance cont r ol" : t o elim inat e backgr ound signals caused by
m ineralized soils
headphone j ack: t o connect an ext ernal headphone ( not incl.)
discrim inat ion cont rol: t o elim inat e ( not ch) undesired m et als
N ot e : t his set t ing influences t he sensit ivit y
needle indicat es m et al t ype
Ele ct r ica l
con du ct ivit y ( S/ m )
63.01 × 10
59.6 × 10
45.2 × 10
37.8 × 10
29.8 × 10
16.6 × 10
CS1 3 0
E upper shaft
F locking nut
G lower shaft
H coil knob
I search coil
M a t e r ia l
6
nickel
6
iron
6
plat inum
6
t in
6
sea wat er
6
drinking wat er
4
Ele ct r ica l
con du ct ivit y ( S/ m )
6
14.3 × 10
6
9.93 × 10
6
9.66 × 10
6
9.17 × 10
4.788
0.0005 ~ 0.05
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