Ludlum Measurements 26 Quick Start 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 OK button

2 – Turn Off

Hold down OK button until it completes 3 second
countdown.

3 – Changing Modes

Press MODE button to cycle through all preselected modes

4 – Initiate Scaler Mode

Change to Scaler Mode, then press OK to begin pre­programmed count time.

5 – Acknowledge Alarms

Press OK button.

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
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.

M

ODE button 3 times (within 4 seconds). Entry to the setup mode is

7 - Setup Parameter Order

Setup Parameter

Unit of Measurement cpm

Response Time 0

Auto-Response Rate
Mode

Count Rate Alarm 0 0-1999 selectable range

Scaler Time 1 minute

Operational Modes 0

Default

Value

F

cpm
cps
0 = Auto Response Rate Mode
1-60 = Fixed Response Time (seconds)

Count Rate F = Fast

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

0 = continuous count
1 sec to 20 minute range (max value = 19 min 60 sec)

0 : RATE, MAX, SCALER
1: RATE, MAX
2: RATE,SCALER
3: RATE

Notes Editing

MODE to select value

OK to select digit
MODE to select value
MODE to select value

S = Slow

(seconds)

(seconds)

OK to select digit
MODE to select value
OK to select digit
MODE to select value
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.