RKI Instruments 65-2380 User manual

RKI Instruments, Inc.
www.rkiinstruments.com
65-2380 Molecular Property Spectrometer
Combustible Gas Detector
Operator’s Manual
Part Number: 71-0595
Revision: P2
Released: 10/14/22
TM

2• 65-2380 Molecular Property Spectrometer
WARNING
Read and understand this instruction manual before operating
transmitter. Improper use of the transmitter could result in bodily
harm or death.
Periodic calibration and maintenance of the transmitter is essential for
proper operation and correct readings. Please calibrate and maintain
this transmitter regularly! Frequency of calibration depends upon the
type of use you have and the sensor types. For most applications,
typical calibration frequencies are between 6 and 12 months but can
be more often or less often based on your usage.

65-2380 Molecular Property Spectrometer • 3
Product Warranty
RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in
materials, workmanship, and performance for a period of one year from date of shipment from
RKI Instruments, Inc. Any parts found defective within that period will be repaired or replaced, at
our option, free of charge. This warranty does not apply to those items which by their nature are
subject to deterioration or consumption in normal service, and which must be cleaned, repaired, or
replaced on a routine basis. Examples of such items are:
• Absorbent cartridges
• Pump diaphragms and valves
•Fuses
•Batteries
• Filter elements
Warranty is voided by abuse including mechanical damage, alteration, rough handling, or repair
procedures not in accordance with the operator’s manual. This warranty indicates the full extent
of our liability, and we are not responsible for removal or replacement costs, local repair costs,
transportation costs, or contingent expenses incurred without our prior approval.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES AND
REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER OBLIGATIONS OR
LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC. INCLUDING BUT NOT LIMITED TO,
THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR APARTI CULAR PURPOSE. INNO
EVENT SHALL RKI INSTRUMENTS, INC. BE LIABLE FOR INDIRECT, INCIDENTAL, OR
CONSEQUENTIAL LOSS OR DAMAGE OF ANY KIND CONNECTED WITH THE USE OF ITS
PRODUCTS OR FAILURE OF ITS PRODUCTS TO FUNCTION OR OPERATE PROPERLY.
This warranty covers instruments and parts sold to users by authorized distributors, dealers, and
representatives as appointed by RKI Instruments, Inc.
We do not assume indemnification for any accident or damage caused by the operation of this gas
monitor, and our warranty is limited to the replacement of parts or our complete goods.

4• 65-2380 Molecular Property Spectrometer
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
MPS Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Junction Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Amplifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mounting the Combustible Gas Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Wiring the Combustible Gas Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Replacing the MPS LEL Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Response Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Overview • 5
Overview
This manual describes the 65-2380 MPS combustible gas detector. This manual also describes
how to install, start up, maintain, and calibrate the detector when used with a gas monitoring
controller. A parts list at the end of this manual lists replacement parts and accessories for the
combustible gas detector.
Specifications
Table 1 specifies the detection ranges and accuracy for each target gas the MPS sensor can detect.
Table 1: Detection Ranges and Accuracy
Target Gas Formula Detection Range Accuracy
at 50% LEL
Butane C4H10 0 - 100% LEL ± 5% LEL
Ethane C2H60 - 100% LEL ± 5% LEL
Hydrogen H20 - 100% LEL ± 5% LEL
Isobutane HC(CH3)30 - 100% LEL ± 5% LEL
Isobutylene C4H80 - 100% LEL ± 5% LEL
Isopropanol C3H8O 0 - 100% LEL ± 10% LEL
Methane CH40 - 100% LEL ± 3% LEL
Methyl Ethyl Ketone C4H8O 0 - 100% LEL ± 5% LEL
Octane C8H18 0 - 100% LEL ± 5% LEL
Pentane C5H12 0 - 100% LEL ± 5% LEL
Propane C3H80 - 100% LEL ± 6% LEL
Propylene C3H60 - 100% LEL ± 5% LEL
Toluene C7H80 - 100% LEL ± 12% LEL
Xylene C8H10 0 - 100% LEL ± 12% LEL
NOTE: The MPS sensor will respond to other combustible gases, but the accuracy has
only been determined for these 14 gases.

6• Applications
WARNING: When using the 65-2380, you must follow the instructions and warnings in this
manual to assure proper and safe operation of the 65-2380 and to minimize the
risk of personal injury. Be sure to maintain and periodically calibrate the 65-
2380 as described in this manual.
Applications
The MPS combustible detector is most effective in the following applications:
• High concentrations of hydrogen sulfide (H2S) or silicones present where sensor
poisoning is a common problem
• High-humidity environments where catalytic or IR sensors may not hold up
• Environments more likely to have mixtures of hydrocarbons present
Table 2: Specifications
Area Classification Explosion-proof for Class I, Groups B, C, and D
Operating Temperature
Range
-20ºC to +50ºC (-4ºF to +122ºF)
Humidity Range 0 - 100% RH (non-condensing)
Pressure Range 80 - 120 kPa
Sampling Method Diffusion
Response Time T90 in 25 seconds
Dead Bands •Methane(CH
4): 3% LEL
• All other gases: 5% LEL

Description • 7
Description
The 65-2380 combustible gas transmitter utilizes a Molecular Property Spectrometer (MPS)
sensor. The MPS sensor is immune to poisons, can be used in high humidity, and does not require
calibration as often as catalytic combustible sensors. It also responds accurately to 14 different
combustible gases.
This section describes the components of the combustible gas transmitter. The transmitter is a 4 -
20 mA type detector head. It consists of the combustible gas detector, amplifier, and junction box.
Figure 1: Component Locations
Amplifier
J-Box
R G
LEL PWR / SIG
W B S
ZERO
MPS LEL Detector
SPAN
Sensor
Current
mA

8• Description
MPS Detector
The MPS LEL detector is made up of the MPS combustible gas LEL detector housed and
encapsulated in a pipe nipple. The pipe nipple has 3/4 NPT threads on each end and a 1-1/4 inch
hex that allows removal or installation of the detector with a wrench. A porous flame arrestor
coated with a hydrophobic film that repels liquids is on one end of the detector and allows sample
gas to enter the detector. Four color coded leads, red, white, green, and black, extend from the
other end of the detector. Use the leads when connecting the detector to the terminal block in the
junction box.
Junction Box
Use the junction box to install the transmitter at a mounting site that is remote from the controller.
The junction box protects the amplifier and wiring connections made to the amplifier. Use the top
3/4 NPT conduit hub to connect wiring from the amplifier to the controller. Use the cover on the
front of the junction box to access the interior of the junction box. The detector and amplifier are
factory installed in the junction box. Three spacers installed on the back of the junction box
control the distance of the junction box from a mounting surface and ensure that there is enough
room to install a calibration cup on the detector during calibration.
Amplifier
The amplifier converts the electrical output from the detector to a 4 - 20 mA signal that
corresponds to the detection range and transmits the signal to a gas monitoring controller. A foam
gasket that orients the amplifier and keeps it from rotating is installed on the bottom of the
amplifier. A label on the amplifier indicates the detector drive current. The amplifier includes the
detector terminal strip, controller terminal strip, span pot, zero pot, and test points (see Figure 2).
Figure 2: Amplifier Component Location
Black - Test Point
LEL PWR / SIG
WB
GS
R
ZERO
SPAN
Sensor
Current
mA
Factory Adjust Pot
Zero Pot
Span Pot
Amplifier
Mounting Screw
Detector Terminal Strip
Controller Terminal Strip
Red + Test Point

Description • 9
Controller Terminal Strip
The controller terminal strip is a three position plug-in style terminal strip located near the top of
the amplifier. Use the controller terminal strip to wire the combustible gas transmitter to a
controller.
Detector Terminal Strip
The detector terminal strip is a four position plug-in style terminal strip located below the
controller terminal strip. Use the detector terminal strip to connect the MPS LEL detector to the
amplifier.
NOTE: The MPS LEL detector is factory-wired to the detector terminal strip. See “Wiring the
Combustible Gas Detector to a Controller” on page 11 for all wiring procedures related
to the transmitter.
Zero Pot
The zero pot is located in the upper left corner of the amplifier (see Figure 2). Use a small flat
blade screwdriver to turn the zero pot’s adjustment screw and adjust the amplifier’s zero (fresh
air) output during the start-up and calibration procedures. Turn the adjustment screw clockwise to
increase the zero output and counterclockwise to decrease the zero output.
Span Pot
The span pot is located to the right of the zero pot (see Figure 2). Use a small flat blade
screwdriver to turn the span pot’s adjustment screw and adjust the amplifier’s gas response output
during the calibration procedure. Turn the adjustment screw clockwise to increase the gas
response and counterclockwise to decrease the gas response.
CAUTION: The amplifier includes two additional potentiometers. They are factory-set. Do not
adjust them.
Test Points
The test points are on the left side of the amplifier (see Figure 2). The test points produce a 100
mV to 500 mV output that corresponds to the transmitter’s 4 to 20 mA output. Use the test points
and a voltmeter to measure the amplifier’s output during the start-up and calibration procedures.
The black test point in the lower left corner is the negative (-) test point and the red test point
below the zero pot is the positive (+) test point.

10 • Installation
Installation
This section describes procedures to mount the combustible gas transmitter in the monitoring
environment and wire the transmitter to a controller.
Mounting the Combustible Gas Transmitter
1. Select a mounting site that is representative of the monitoring environment. Consider the
following when you select the mounting site.
• Select a site where the transmitter is not likely to be bumped or disturbed. Make sure there
is sufficient room to perform start-up, maintenance, and calibration procedures.
• Select a site where the target gas is likely to be found first. For lighter gases, mount the
detector near the ceiling; for heavier gases, mount the detector near the floor.
Figure 3: Mounting the Combustible Gas Transmitter
2. At the monitoring site you select, hang or mount the junction box with the detector facing
down (see Figure 3).
.382.70
Rubber
Spacer,
3X
.75
3/4 NPT
Female
3.65
J-Box
MPSLEL Detector
7.10 MAX