Ludlum 78-6

Handheld survey meter

Ludlum 78-6 – handheld survey meter from Ludlum Measurements. Weight as specified: 2.9 kg, including batteries.

Detector: NaI(Tl) scintillator, 2.5 × 2.5 cm, coupled to a photomultiplier1
Weight as specified: 2.9 kg, including batteries1

Download product sheet (PDF)All values with references – for tender documents

Specifications checked against the manufacturer’s documents on 2026-10-16

Manufacturer’s product page (opens in a new tab)

Overview

Nuclear power & nuclear technology Defence, security & preparedness Emergency services & first response Environmental monitoring & radiation protection Industry & quality control

Specifications

The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.

Detector

Detector	NaI(Tl) scintillator, 2.5 × 2.5 cm, coupled to a photomultiplier1

Performance

Linearity	±10 %1

Measuring range

Counting ranges	Two-scale meter face presenting 0 - 50 µR/hr with full-scale range positions of 5000, 500, and 50; and 0 - 25 µR/hr with full-scale positions of 250 and 251

Electronics & signal

Detector bias	Variable from 400 to 1500 Vdc, electronically regulated to within 1 %1

Power & battery

Power supply	2 "D" batteries1
Battery life and conditions	Approximately 1000 hours with alkaline batteries1

Mechanical

Dimensions (H × W × L)	17.7 x 10.2 x 114 cm retracted; 396 cm fully extended1
Weight as specified	2.9 kg, including batteries1

Environment & ratings

Operating temperature	-20 to 50 °C1

The data comes from the manufacturer’s published documents. Manufacturers may change specifications; the current configuration and performance are confirmed in the quotation.

Documents

PDFDatablad (PDF)Datasheet · Ludlum

Sources

The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.

1
Model 78-6 – Stretch Scope Survey Meter
Publisher: Ludlum MeasurementsProduct page Specifications tab, 'Detector'; Specifications tab, 'High Voltage'; Specifications tab, 'Linearity'; Specifications tab, 'Power' … Checked 2026-10-16