Detection Method: Tunable Diode Laser Absorption 

Spectroscopy (TDLAS)

Measurement Range: 0 to 99,999 ppm-m

Sensitivity: 5 ppm-m at distances from 0 to 50 ft (15 m)

10 ppm-m or better at distances from 

50 to 100 ft (15 to 30 m)

Intrinsic Safety: Class 1 Division 1 Group D, T3 in accordance 

with UL 913 & CSA C22.2 No 157, 

MetLab Listing #E112840

Detection Distance: 100 ft (30 m) nominal. Actual distance may vary due to background type and conditions.

Beam Size: Conical in shape with a 22” diameter at 100 ft (56 cm at 30 m)

Detection Alarms Modes: Digital Methane Detection (DMD): Audible tone relative to concentration when detection 

threshold exceeded

Adjustable Detection Alarm Level from 0 to 255 ppm-m

Pure Tome: Continuous audio tone relative to concentration

Adjustable Volume: 8 Levels 

System Fault Warning: Unique audible tone and indication on the display

Self Test & Calibration:	 Built-in Self Test and Calibration function verifies operation and adjusts laser wavelength for

maximum sensitivity. Test gas cell integrated within carrying case.

Compliance: EMC (EN61000-6-2, EN6100-6-4) 

Laser Eye Safety: IR Laser: Class I

(CDRH, ANSI and IEC) Green Spotter Laser: Class IIIa; Do not stare into beam or view directly with optical 

instruments

Communications: RS232 Standard, Bluetooth optional

Display: Large, easy to read backlit LCD (.75” Numeric) 

Operating Temperature: 0° to + 122° F (-17° to 50° C)

Humidity: 5 to 95% RH, non-condensing

Enclosure: IP54 (Water splash and Dust resistant)

Instrument Weight: 10 lbs (Transceiver 3 lbs, Controller 7 lbs); (4.5 kg; 1.3 kg , 3.2 kg)

Carry Case: 14 lbs; 34” x 9 1⁄2” x 14” (6.4 kg; 86 cm x 24 cm x 36 cm)

Battery: Internal, rechargeable, Li ion battery pack, 11.1 Vdc

Battery Run Time: 8 hours at 32° F without backlight on, minimum

Battery Charging: External, in-line, 110-240 Vac, 50 / 60 hertz, international, 19 Vdc power supply

Charge Time, Maximum: 8 hours

Charging Indicator: Integrated into controller panel

Shoulder Strap: Single over the shoulder padded strap with Ergonomic dual strap and belt system

TECHNICAL SPECIFICATIONS:

1-800-HEATH-US • www.heathus.com 

6/13
Revolutionary Technology

The portable, reliable 

Remote Methane Leak 

Detector (RMLD-IS®) 

changed the way methane 

surveys are conducted. 

Instead of having to 

walk the entire length of 

the service line to check 

for methane leaks...the 

RMLD-IS quickly and 

efficiently detects leaks up 

to one hundred feet away 

allowing remote detection 

of hard-to-reach areas and 

difficult terrains. Remote 

detection allows the user 

to safely survey difficult 

to reach areas, such as 

busy roadways, yards with 

large dogs, locked gates, 

compressor stations, offshore 

platforms and other hard to 

access places. 

For utilities and their 

employees, this timesaving method represents 

the potential for significant 

productivity gains, reduced 

operations and maintenance 

costs, and a safer survey.

Tunable Diode Laser 

Absorption Spectroscopy

Available gas detectors 

that deploy technologies such 

as flame ionization must be 

positioned within the leak 

plume to detect the presence 

of methane. The RMLD-IS 

does not have to be within 

the gas plume because it 

uses laser technology known 

as Tunable Diode Laser 

Absorption Spectroscopy. 

When the laser passes 

through a gas plume, the 

methane absorbs a portion of 

the light, which the 

RMLD-IS then detects. This 

quantum leap in technology 

makes it possible to detect 

methane leaks along the sight 

line without always having 

to walk the full length of the 

service line. 

Components

The RMLD-IS 

consists of two interactive 

components; a transceiver 

subsystem and a signal 

processing/user interface 

controller. The transceiver 

has two lasers; an infrared 

laser beam that is non-visible 

and is continuously on while 

the unit is turned on. The 

green spotter laser is similar 

to those used for presentation 

pointers and is turned on by 

the operator depressing the 

trigger button. 

How Does It Work?

When the infrared laser 

beam is transmitted from the 

launch port some of the laser 

light is reflected by a normal 

background such as brick, 

concrete, grass, etc., to the 

detector. This reflected light 

is collected and converted 

to an electrical signal that 

carries the information 

needed to deduce the relative 

methane concentration. This 

signal is processed so that 

methane concentrations 

can be reported in parts 

per million meter or 

ppm-m. The laser has a 

nominal distance of up to 

100 feet and is selective 

to methane only. It will 

not false alarm on other 

hydrocarbons.

®

RMLD-IS

Intrinsically Safe

 With its intrinsically 

safe rating the RMLDIS opens a new realm of 

survey applications such as:

• Offshore Platforms

• Plant and Industrial 

 Inspections

• Compressor Stations

• Production Facilities 

 – gas gathering, drilling 

 sites etc.

• LNG Ship Inspections

• First Responders for Leak 

 Investigation

• First Responders to Odor 

 Complaints

• Gas Processing Plant 

 Inspections