Ludlum Measurements 26 User manual

Model 26 Quick Start Guide
Rev 05/14/2013
This document presents a quick overview on how to use the two button controls (OK, and Mode) for operating
and editing parameters on the Ludlum Model 26. See the manual for complete detail.
1 – Turn On
Momentarily press OKbutton
2 – Turn Off
Hold down OKbutton until it completes 3 second
countdown.
3 – Changing Modes
Press M ODE button to cycle through all preselected modes
4 – Initiate Scaler Mode
Change to Scaler Mode, then press OKto begin pre-
programmed count time.
5 – Acknowledge Alarms
Press OKbutton.
6 - Initiating Setup
To enter setup mode, power down the Model 26, then turn the unit back on.
When the unit reads “0”, press the MODE button 3 times (within 4 seconds). Entry to the setup mode is
confirmed when you see either the cpm or cps blinking.
To simply view the parameters don’t press any buttons and the display will automatically advance every four
seconds to the next parameter.
The unit will return automatically to normal operation after the last parameter is presented.
Note: An internal switch is available to put the instrument into a Protect Mode disallowing any editing. See section
8 – Protective Mode Switch to change switch position.

7 - Setup Parameter Order
Setup Parameter Default
Value Notes Editing
Unit of Measurement cpm cpm
cps
MODE to select value
Response Time 0 0 = Auto Response Rate Mode
1-60 = Fixed Response Time (seconds)
OK to select digit
MODE to select value
Auto-Response Rate
Mode F
Count Rate F = Fast
(seconds)
S = Slow
(seconds)
Less than 3 kcpm 5 10
Between 3 - 4 kcpm 4 8
Between 4 - 6 kcpm 3 6
Between 6 – 12 kcpm 2 4
More than 12 kcpm 1 2
MODE to select value
Count Rate Alarm 0 0-1999 selectable range OK to select digit
MODE to select value
Scaler Time 1 minute 0 = continuous count
1 sec to 20 minute range (max value = 19 min 60 sec)
OK to select digit
MODE to select value
Operational Modes 0
0: RATE, MAX, SCALER
1: RATE, MAX
2: RATE,SCALER
3: RATE
MODE to select value
8 – Protective Mode Switch
An internal DIP (dual inline position) switch can be set to either permit editing parameters (see section 6 – Initiating
Setup) or to Protect against any editing by users. To gain access to the DIP switch, remove the batteries, then unscrew the
4 screws holding the instrument together so the instrument halves become separated.
Once separated, gently move the GM pancake
detector from its holder over to one side while
leaving the wire intact. With the detector out of
the way, you will see the dual switches as
indicated in the picture.
When both switches are slid to the LEFT
position it is in the Edit Mode (default).
When the bottom switch is in the Right Position,
it is in the Protect Mode.