Ludlum Measurements 26-2 User manual

LUDLUM MODEL 26-2 FRISKER
USER’S MANUAL
December 2016
Serial Number PF002406
and Succeeding Serial Numbers

Model
LUDLUM MODEL 26-2 FRISKER
USER’S MANUAL
December 2016
Serial Number PF002406
and Succeeding Serial Numbers

Model26-2Frisker User’s Manual

Model26-2Frisker User’s Manual
STATEMENT OF WARRANTY
Ludlum Measurements, Inc. warrants the products covered in this manual to be free of
defects due to workmanship, material, and design for a period of twelve months from
the date of delivery. The calibration of a product is warranted to be within its
specified accuracy limits at the time of shipment. In the event of instrument failure,
notify Ludlum Measurements to determine if repair, recalibration, or replacement is
required.
This warranty excludes the replacement of photomultiplier tubes, G-M and
proportional tubes, and scintillation crystals which are broken due to excessive
physical abuse or used for purposes other than intended.
There are no warranties, express or implied, including without limitation any implied
warranty of merchantability or fitness, which extend beyond the description of the
face there of. If the product does not perform as warranted herein, purchaser’s sole
remedy shall be repair or replacement, at the option of Ludlum Measurements. In no
event will Ludlum Measurements be liable for damages, lost revenue, lost wages, or
any other incidental or consequential damages, arising from the purchase, use, or
inability to use product.
RETURN OF GOODS TO MANUFACTURER
If equipment needs to be returned to Ludlum Measurements, Inc. for repair or calibration, please
send to the address below. All shipments should include documentation containing return shipping
address, customer name, telephone number, description of service requested, and all other necessary
information. Your cooperation will expedite the return of your equipment.
LUDLUM MEASUREMENTS, INC.
ATTN: REPAIR DEPARTMENT
501 OAK STREET
SWEETWATER, TX 79556
800-622-0828 325-235-5494
FAX [phone]

Model26-2Frisker User’s Manual
Table of Contents
Introduction 1
Getting Started 2
Unpacking and Repacking 2-1
Battery Installation 2-2
Instrument Operational Test 2-3
Detector Failure Diagnostics 2-4
Detector Over Range 2-4
Instrument Use and Controls 2-5
Rate Mode Operation 2-6
Max Mode Operation 2-7
Timed Frisk Mode Operation 2-8
Specifications 3
Setup Mode 4
Setup Overview 4-1
Entering Setup Mode 4-2
Default Setup Values 4-3
Setup Mode Operation 4-3
Safety Considerations 5
Environmental Conditions for Normal Use 5-1
Warning Markings and Symbols 5-1
Cleaning and Maintenance Precautions 5-2
Revision History 6
Recycling 7

Model26-2Frisker User’s Manual Section1
Ludlum Measurements, Inc. Page 1-1 December 2016
Introduction
The Model 26-2 is an ergonomic, lightweight instrument intended for
contamination frisking. The instrument features a large backlit LCD
(liquid crystal display), LEDs which signify alarm and non-alarm
conditions, a piercing audio warning, and easy, intuitive use in a single-
handed platform. A comfortable wrist strap and lanyard are also
included for keeping the instrument close and secure. The unit body is
made of lightweight but durable plastic. It is intended for outdoor use
and can resist splashing water.
There is also a headphone option available (not included). The
instrument can be modified to include a standard 1/8 inch headphone
jack (part number 4498-538).
Three modes of operation are available for the Model 26-2; RATE,
MAX, and TIMED FRISK. RATE mode operation measures
contamination from background levels up to 1.99 kcps or 100.0 kcpm.
MAX mode is used to capture the highest count rate detected –useful
for finding peak contamination rate, or frisking when the display is not
visible. TIMED FRISK mode allows the user to perform a
contamination frisk for a predetermined time. The display will be
automatically backlit if light levels are low. The display backlight can
also be configured for ‘Continuous On’ operation. RATE and MAX
modes can be silent or may utilize a 'click' audio; the 'click' audio is
always on during TIMED FRISK mode. RATE and TIMED FRISK
modes feature non-latching continuous tone alarms for count rates
above alarm levels. The continuous tone alarms in MAX mode will
latch with the captured highest count rate, and will clear when the MAX
count is acknowledged and then reset. The RATE, MAX, and TIMED
FRISK modes can also be disabled, simplifying the unit even further
The Model 26-2 allows up to three count rate alarm settings, which are
automatically evaluated from lowest to highest values. Four LEDs show
the current alarm status; a green LED for no alarm, and three red
LEDs, which work in combination to signify the alarm level.
Section
1

Model26-2Frisker User’s Manual Section1
Ludlum Measurements, Inc. Page 1-2 December 2016
The Model 26-2 utilizes a standard 15 cm2(0.9 in2) Geiger-Mueller
"pancake" detector, which can detect alpha, beta, or gamma radiation.
Caution is needed with handling the instrument because of the thin
radiation detector's window.
Setup of the instrument is accomplished through the front-panel
buttons. The advanced user or administrator can set:
Response Rime
Auto-Response Rate (Fast or Slow)
Up to three Count Rate Alarm Levels
Frisk Time
Available Operational Modes
Setup can be disabled via the internal switch on the Model 26-2 in order
to protect settings.
The unit is operated with two AA batteries for operation from -40 to 65
°C (-40 to 150 °F). Battery life should be approximately 1000 hours
under normal usage. A low-battery indicator on the LCD warns when
less than 16 hours of battery life remain.

Model26-2Frisker User’s Manual Section2
Ludlum Measurements, Inc. Page 2-1 December 2016
Getting Started
Unpacking and Repacking
Remove the calibration certificate and place it in a secure location. Remove
the instrument and ensure that all of the items listed on the packing list are
in the carton. Check individual item serial numbers and ensure calibration
certificates match. The Model 26-2 serial number is located on a label on the
front of the unit.
To return an instrument for repair or calibration, provide sufficient packing
material to prevent damage during shipment. Be aware that the thin mica
window of the detector may be damaged (imploded) because of pressure
differentials if the unit is shipped by air. Protect the unit by putting it inside
a sealed can or other protective enclosure.
Every returned instrument must be accompanied by an Instrument
Return Form, which can be downloaded from the Ludlum website at
www.ludlums.com. Find the form by clicking the “Support” tab and
selecting “Repair and Calibration” from the drop-down menu. Then choose
the appropriate Repair and Calibration division where you will find a link to
the form.
Section
2

Model26-2Frisker User’s Manual Section2
Ludlum Measurements, Inc. Page 2-2 December 2016
1. Grab the ring on the screw.
2. Turn the ring one quarter turn
counter-clockwise.
3. Release and remove the battery cover.
4. Replace two each AA batteries.
5. Firmly insert the barb of the battery
cover completely into the body of the
Model 26-2.
6. Replace the cover and turn ring one
quarter of a turn clockwise to secure.
Battery Installation
A low-battery indicator appears at the bottom of the LCD when less than 16 hours of battery life remain.
When this indicator is present, follow these steps to replace the two standard AA batteries:
Warning: If this procedure
is not followed correctly,
and the barb is not inserted
into the body of the
instrument correctly, the
barb may break off.

Model26-2Frisker User’s Manual Section2
Ludlum Measurements, Inc. Page 2-3 December 2016
Instrument Operational Test
Turn the instrument ON by pressing the ON/ACK button for about a
second, and then releasing. The instrument should activate all the LCD
segments and the audio, and cycle through the LEDs. Observe the device
during this time. If any LCD segments are missing, or if audio or any LEDs
fail to work, the device is in need of repair. Please refer to Figure 1 below.
Figure 1: Startup display for Model 26-2, with all LCD segments shown.
It then displays the firmware version number before displaying the current
count rate, starting at 0 cpm (or 0.0 cps). Ensure that the low-battery
indicator is not present. If the low-battery indicator is present, replace the
batteries as soon as possible. Under extremely low-battery conditions, be
aware that the unit may not even turn on or may turn itself off abruptly.
A reference reading with a check source, 1 µCi (37 kBq) of 137Cs for
example, should be obtained at the time the instrument is received in the
field. Small check sources of radiation are available from Ludlum
Measurements. While exempt from many regulations because of their small
size, these sources are large enough to produce a response on this
instrument. The detector's position is indicated by the circular screen on the
back of the Model 26-2: the seam between the enclosure halves indicates the
approximate center of the detector. If this procedure is done routinely with
the same radiation source, instrument malfunction may be detected when
anomalous readings are observed. If at any time the instrument fails to read
within 20% of the reference reading when using the same check source, it
should be sent to a calibration facility for recalibration and/or repair.
Example log reading:
Check Source # Count Rate
Once this procedure has been completed, the instrument is ready for use.