35-3001-06H-DIL Hydrogen/Oxygen Sample-Draw Detector • 1
Overview
This operator’s manual describes the 35-3001-06H-DIL hydrogen/oxygen sample-draw detector.
This manual also describes how to install, start up, maintain, and calibrate the sample-draw detector
when using it with a gas monitoring controller. A parts list at the end of this manual lists
replacement parts and accessories for the sample-draw detector.
About the 35-3001-06H-DIL
The 35-3001-06H-DIL is designed to monitor hydrogen and oxygen in an inerted area (an area that
has no, or almost no, oxygen present). The catalytic LEL sensor used to detect hydrogen must have
at least 5% oxygen present to detect gas properly. A dilution fitting installed in the flow system
after the oxygen sensor and before the LEL sensor allows enough air to enter the gas sample so that
the LEL sensor has enough oxygen to function properly. The dilution ratio is approximately 1:1 but
will vary slightly with increased sample line lengths. The longer the sample line, the more dilution
air will enter the gas sample through the dilution fitting. Because of this, it is important when
calibrating the detector head to apply the calibration gas to the sample line inlet if a sample line is
installed. In addition, because the detector head includes internal dilution, it must be calibrated
using a sample bag instead of a demand flow regulator. See “Calibration, LEL Sensor” on page 19
and “Calibration, Oxygen Sensor” on page 21 for detailed calibration instructions.
Specifications
Table 1 lists specifications for the hydrogen/oxygen sample-draw detector. See the controller
Operator’s Manual for information specific to the controller.
Table 1: Specifications
Target Gases and Detection Range
Hydrogen: 0 - 100% LEL
Oxygen: 0 - 25% volume
Input Power
24 VDC Nominal (18.5 VDC - 30 VDC)
Construction (housing)
Fiberglass/polyester (NEMA 4X)
Dimensions
8.5 in. H x 6.5 in. W x 4.25 in. D
Weight
4.5 lbs.
Sampling Method
Sample-draw
Sample Flow
2.7 SCFH typical, with no inlet or exhaust line
Low Flow Setpoint
1.0 ± 0.1 SCFH, measured in the sample inlet line
Sensor Flow
0.8 SCFH (nominal)
Maximum Recommended Inlet/
Exhaust Line Length for
1/4” O.D. x 1/8” I.D. Tubing
Inlet
Exhaust
50 feet
0 feet
* RKI Instruments, Inc. does not recommend installing this tubing
size on both the inlet and exhaust.
