Ludlum 9-4RF

Handheld survey meter

Ludlum 9-4RF – handheld survey meter from Ludlum Measurements. Detector: Air ionization chamber. Weight with batteries: 1.9 kg.

Detector: Air ionization chamber1
Weight with batteries: 1.9 kg1

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

Key features

Detector: Air ionization chamber
Measurement range: 0–500 mSv/h
Energy response: Within 20 % of true value, 40 keV–2 MeV

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	Air ionization chamber1
Chamber volume	220 cm³1

Measuring range

Measurement range	0–500 mSv/h1
Energy response	Within 20 % of true value, 40 keV–2 MeV1

Power & battery

Power supply	2 D batteries1
Battery life	400 hours1
Weight with batteries	1.9 kg1

Mechanical

Dimensions (H × W × L), with handle	23.4 × 8.9 × 21.6 cm1

Environment & ratings

Operating temperature	−20 to +50 °C1

General

Pressure compensation	70–106 kPa1

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 9-4RF – RF-Immune Air Ion Chamber Survey Meter
Publisher: Ludlum MeasurementsProduct page Product description; Specifications tab, 'Detection Range'; Specifications tab, 'Energy Response'; Specifications tab, 'Chamber Volume' … Checked 2026-10-16