SF Ratemeter 5135.55 User manual
08.06.95 Ae 5135.55
Instruction manual for the Ratemeter no. 5135.55
The Ratemeter no. 5135.55 is a battery operated
portable GM-counter equipped with a built-in GM-tube.
The built-in GM-tube is sensitive to Alpha-, Beta-, and
Gamma-radiation.
The app. is equipped with an analogue moving coil
instrument with 2 measuring ranges: 0 - 100 and 0 -
1000 pulses/sec. Choice of range is done by means of
a pushbutton and indicated by LED’s.
The app. is battery operated (the battery compartment
holds a 9 V battery IEC type 6F22), but may also be
mains operated utilizing a mains adapter e.g. no.
3550.10. When connecting a mains adapter the battery
will automatically be disconnected.
Pos.1 ON/OFF switch. The app. is switched On
respectively OFF by pushing this button.
Pos. 2 Analogue moving coil instrument for monitoring
the measured pulses. Choose between 2 ran-
ges by means of the pushbutton pos. 3.
Pos. 3 Pushbutton range selector, choice between
2 ranges: 0 - 100 pulses/sec.
0 - 1000 pulses/sec.
Pos. 4 Range indicator, the LED for the chosen range
will be lit.
Pos. 5 Battery indicator. The LED’s indicating the
measuring range will start flashing when the
battery charge is too low. If you keep the app.
in operation the battery charge will drop to a
level thus that the LED will be lit continuously
but very weakly. The battery is spent and
should be replaced in both cases.
N.B. we recommend the use of alkaline
batteries only, IEC type 6F22.
Pos. 6 Battery compartment for 1 pcs. 9 V battery
type IEC 6F22.
Pos. 7 Jack-terminal 3.5 mm dia. for connecting a 9 V
mains adaptor tip positive - e.g. our no. 3550.10
or similar.
1
2
3
4
6
7
10
9
5
8
Frederiksen
Viaduktvej 35 - DK-6870 Ølgod - Tlf 7524 4966 - Fax. 7524 6282
Pos. 8 Built-in GM-tube. The tube’s window is made
of a very thin and delicate material which is
easily destroyed. For this very reason it has
been equipped with a protective cap which
may be left on in most cases except when
measuring alpha-radiation. The cap, is
provided with a venting hole to avoid vacuum
when removing it or the opposit when
mounting it again. I.e. it is of the utmost
importance that the venting hole is
uncovered when mounting or removing the
cap.
Pos. 9 Output terminal 3.5. mm dia. for TTL pulses
(0 - 5 V).
Pos. 10 Analogue output terminal 3.5. mm dia.
Technical specifications for app.:
Operating voltage: 9 volt DC
Current: ca. 20 mA
Effect: ca. 180 mW
Output terminal f. pulses: TTL level (0 - 5 V)
Output terminal f. ext. meter:0 - 1 V
Dims.: 205 x 109 x 53 mm
Weight incl. battery: 720 g
Technical specifications for the tube:
The tube is sensitive to alpha, beta and
gamma radiation.
Plateau threshold voltage (Vb1): 450 V
Plateau length (Vb2 - Vb1): 150 V
Recommended supply voltage: 500 V
Window specifications:
Thickness: 1.5 to 2.0 mg/cm˝
Usefull diameter: 9.14 mm
Material: Mica
Gas filling: Neon, Argon and Halogen
Dead time,
at recommended supply voltage: 90 mS
Plateau:
The plateau is the part of the diagramme
where the number of counts per second
is (almost) independant of the voltage
