PASCO SN-7927A User Manual

Instruction Sheet
for the PASCO
Model SN-7927A

012-07905B

Geiger-Müller Counter

Equipment

The Geiger-Müller Counter is equipped with a built-in
Geiger-Müller (G-M) tube and integral power supply.
Its power indicator, an LED, lights when an operating
voltage is supplied to the unit. The unit has a buzzer that
emits an audible signal for each pulse that is recorded. A
plastic cap that provides protection for the delicate mica
membrane is included. The cap has a venting hole that
prevents the creation of a vacuum or pressure when the
cap is removed or replaced.

Introduction

The PASCO SN-7927A Geiger-Müller Counter senses
beta, gamma, and alpha radiation when connected to a
computer interface such as the ScienceWorkshop 500 or
750 Interface. The built-in power supply allows direct
connection of the Geiger-Müller Counter to the input ter­minal of any computer interface that provides an avail­able operating voltage of +5 V, 20 mA.

Use the Geiger-Müller Counter in all experiments de­scribed in the SE-7997 LabNet Geiger-Müller Interface
manual and experiment guide, as well the SN-7973
Nuclear Science experiment manual. Its performance is
nearly identical to that of the SE-7970A Geiger-Müller
Probe, with several advantages:

• direct connection to the Science Workshop 500 or 750

Interface (no additional power supply or adapter
needed)

• versatile positioning options (hand-held or adjustable

on a rod stand) that allow the device to be held closer
to the radiation source

• audible feedback: the device beeps when it registers a

count

➤ Caution: The mica window is extremely del-
icate. Do not cover the hole in the protective cap
when removing or replacing it, and leave the cap
in place except when alpha radiation is being
measured.

Data:
Window material: Mica
Diameter: 9.14 mm
Density: 1.5-2 mg/cm2
Count rate: max. 11,111 per sec (from a min. dead-time
of 90 microseconds).

Required equipment:

- computer interface that provides an available operat­ing voltage of +5 V, 20 mA, such as the Science
Workshop 500 or 750 Interface.

Additional equipment suggested:

- Small Base and Support Rod (SE-9451)

- Radioactive Sources (SN-8110)

Never touch the mica window!

© 2001 PASCO scientific

Geiger-Müller Counter 012-07905B

Operation with DataStudio and a

Workshop 500 or 750

➀ Plug the stereo phone plug into any digital port on the

interface box.

➁ Start DataStudio and select the geiger counter in the

Setup window for the correct port.

➂ Select a data display.

➤ NOTE: The geiger counter displays the number of

counts in a given period of time. To change the time
period, adjust the sampling rate.

Computer Interface

Science

Nuclear Safety

Most radioactive sources available to educators
are very low level isotopes referred to as “li­cense free” sources. This does not mean, how­ever, that these materials represent no hazard to
students. The Nucleus, P.O. Box R, Oak Ridge,
Tennessee, 37830, has provided the following
guidelines for use of low-level radioactive mate­rials in classroom environments:

➀ Eating, drinking, and the application of cos-

metics in the laboratory are not permitted.

➁ Pipetting by mouth is never permitted. Use

suction devices such as pipette fillers.

➂ Gloves and lab coats should be worn when

working with all liquid radioisotopes.

➃ Before leaving the lab, wash your hands

thoroughly then check for possible contami­nation with a survey instrument.

➄ All radioactive liquid wastes are to be poured

into the liquid waste container, NEVER into
a sink.

➅ Report ALL spills, wounds, or other emer-

gencies to your instructor.

➆ Maintain good housekeeping at all times in

the lab.

➇ Store radioactive materials only in the desig-

nated storage area. Do not remove sources
from the lab.

Copyright Notice

The PASCO scientific SN-7927A Geiger-Müller Counter
instruction sheet is copyrighted and all rights reserved.
However, permission is granted to non-profit educational
institutions for reproduction of any part of this manual
providing the reproductions are used only for their labora­tories and are not sold for profit. Reproduction under any
other circumstances, without the written consent of
PASCO scientific, is prohibited.

Limited Warranty

PASCO scientific warrants the product to be free from
defects in materials and workmanship for a period of one
year from the date of shipment to the customer. PASCO
will repair or replace, at its option, any part of the product
which is deemed to be defective in material or workman­ship. The warranty does not cover damage to the product
caused by abuse or improper use. Determination of
whether a product failure is the result of a manufacturing
defect or improper use by the customer shall be made
solely by PASCO scientific. Responsibility for the return
of equipment for warranty repair belongs to the customer.
Equipment must be properly packed to prevent damage
and shipped postage or freight prepaid. (Damage caused
by improper packing of the equipment for return shipment
will not be covered by the warranty.) Shipping costs for
returning the equipment, after repair, will be paid by
PASCO scientific.

Equipment Return

Should the product have to be returned to PASCO scien­tific, for whatever reason, notify PASCO scientific by
letter or phone BEFORE returning the product. Upon
notification, the return authorization and shipping instruc­tions will be promptly issued.

Address: PASCO scientific

10101 Foothills Blvd.
P.O. Box 619011

Roseville, CA 95678-9011
Phone: [phone]
FAX: [phone]



2