Model 26S

Integrated Scintillator Frisker

Part Number: 48-4380

Features

• Lightweight Design - Only 0.35 kg (0.75 lb)
• Employs 1 x 1 Equivalent Scintillator Detector
• Sigma Audio (or Click Audio Possible) & Alarm Beep
• Displays in mR/hr, µSv/h, dpm, Bq, cpm, or cps
• Simple Three-Button Operation
• Count Rate, Exposure, Dose, and Counting Alarms
• Automatic Display Backlight
• Bright Red Flashing ALARM LED

The Ludlum Model 26S incorporates electronics and a miniature scintillation detector in an ergonomically designed, ruggedly-constructed, and water-resistant housing. The integrated unit doesn’t have a detector cable, thereby simplifying the process of frisking. The optimized configuration includes a standard 1 x 1 equivalent detector, loud Sigma audio, and large auto-ranging LCD display with automatic backlighting. These features are combined in one convenient package making it easy to detect and measure gamma fields.

Operation of the Model 26S is kept simple through the use of just three buttons that are strategically placed for one-handed operation. Three modes of operation – RATE, MAX, and COUNT – are available. The RATE mode displays current radiation levels in terms of rate. MAX mode captures the highest rate detected so it is possible to determine a peak rate during frisking operations when the display is not visible. COUNT mode allows the operator to perform a survey for a predetermined time. The user-selected units can display results in a measurement of scaler counts, activity (disintegrations), time-averaged rates, or even accumulated dose.

Low-power circuitry means two standard “AA” sized batteries deliver hundreds of hours of instrument operation. The parameters may be protected via internal dipswitch, or the calibrator may allow the user to adjust them. Other features include a backlight triggered by low-level ambient lighting (may be configured for “Continuous On” operation) and audio that may be silenced for both RATE and MAX modes.

• Specifications
• Graphs
• Options
• Documents
• Response Kit

• Specifications
• Graphs
• Options
• Documents
• Response Kit

Specifications

Detector	2.5 x 1.9 cm (1 x 0.75 in.) CsI(Tl) scintillator (energy dependent, see response curve)
Gamma Sensitivity (137Cs)	165 kcpm per mR/hr
Energy Range	From 40 keV to 3 MeV
Exposure Linearity	± 10% from background to 200 µSv/h (20 mR/hr)
Count Rate Linearity	± 10% from 8 c/s to 8 kcps (200 c/m to 999 kc/m)
LCD Display	3½ digit LCD with large 12.7 mm (0.5 in.) digits Units: (k)c/s, (k)c/m, (k)d/m, (k)d/s, µR/hr, µSv/h Indicators: low-battery, MAX, ALARM
Display Range	0.00 c/s to 19.9 kc/s 0 c/m to 999 kc/m 0.00 d/s to 19.9 kd/s 0 d/m to 999 kd/m 0.00 to 200 µSv/h 000 µR to 20 mR/hr
Controls	ON/OFF/QUIET: Press to turn ON, Tap to alternate between 'click' audio and QUIET, Hold for OFF MODE: Select RATE (count rate), MAX (captures peak rate), or COUNT (preset count time) UNITS: alternates between Primary and Secondary units
Backlight	Built-in ambient light sensor automatically activates low-power LED backlight, or may be configured for ‘Continuous On’ operation (will reduce battery life)
Response Time	User-selectable from 1 to 60 seconds, or Auto-Response Rate FAST or SLOW
Alarms	Count rate and scaler alarm setpoints adjustable over the display range
Loss of Count Protection	After 60 seconds of no pulses from detector, unit will flash a zero reading and the alarm audio will be triggered
Sigma Audio	Greater than 60 dB at 0.6 m (2 ft), approximately 4.5 kHz
Power	Two alkaline "AA" batteries
Battery Life	Approximately 200 hours of operation
Construction	High-impact plastic with water-resistant rubber seals and separate battery compartment
Environmental Rating	NEMA 3 / IP 53
Temperature Range	-20 to 50 °C (-4 to 122 °F)
Size (H x W x L)	4.6 x 6.9 x 27.2 cm (1.8 x 2.7 x 10.7 in.)
Weight	0.35 kg (0.75 lb)

---

Graphs

---

Options

Option	Description	Part Number
Headphone Jack	Adds headphone jack to instrument.	4498-538
Canvas Holster	Canvas holster with belt clip for Model 26 Series instruments.	2312577
Model 180-28	Sample holder for Model 26-Series friskers.	47-3948
Extendable Pole	A lightweight pole with 5 telescoping sections and an adjustable clamp to hold a Model 26 Series Frisker. Useful to access high, low, or other hard to reach places. Length: 0.55 m (1.8 ft) collapsed, 1.5 m (4.92 ft) fully extended	4519-077
Transport & Storage Case for Model 26 and Extendable Pole	Rugged, waterproof, airtight, hard-shell case with dense foam padding to hold Model 26 and extendable pole.	2311064

---

Documents

• Data Sheet
• Product Manual
• Model 26 Series Comparison Table

---

Response Kit

An emergency response kit consisting of the Model 26-3 and Model 26S packaged in a rugged transport and storage case is also available. Click the link below to learn more.

Model 26-RK

---