Introduction; Overview; Detection Options; Broadband Vs. Gas Specific - Emerson MRLDS-250 Installation And Operation Manual

1

Introduction

1.1.

Overview

The MRLDS-250 NDIR (non-dispersive infrared) is a
state-of-the-art fixed gas detector that can detect a
wide range of refrigerant gases. The MRLDS-250 can
be used on a stand-alone basis or integrated into
controls or a Building Management System (BMS).
The MRLDS-250 can be used in locations that require
continuous monitoring and to add gas detection
solutions to an existing system.
Figure 1-1 - MRLDS-250 Components
1.2.

Detection Options

1.2.1. Broadband vs. Gas
Specific
The MRLDS-250 NDIR refrigerant gas detectors are
available in two versions: broadband and gas-specific.
1.2.2.

Broadband Gas Detection

The broadband gas detector (P/N 809-0030) is used as
a general purpose gross leak detector and is factory
tested and certified. It is shipped from the factory with
accuracy as shown in Table 1-1 (gas dependent). If
Overview
more accurate detection is needed, gas specific
versions are available, which are factory certified and
calibrated to the target refrigerant.
The broadband gas detector combines refrigerants
into 4 groups shown in Figure 1-2. Measurement
performance is based on an average response profile
for all of the gases within the group.
Value
for
Group#
Param
1
11
1 P.-11 = 1
2 P.1-11 = 2
3 P.-11 = 3
4 P.-11 = 4
Table 1-1 Broadband Gas Groups
As
Refrigerant Shipped
Accuracy
R134a ±25%
R404a ±35%
R407a ±25%
R407c ±20%
R407f ±20%
R410a ±20%
R427a ±15%
R452B ±40%
R507 ±35%
HFO1233ZD ±35%
R448A ±40%
R449A ±40%
R422a ±25%
R422d ±20%
HFO1234YF ±25%
HFO1234Ze ±25%
R452A ±25%
R513A ±35%
R514A ±20%²
R22 ±25%
R32 ±35%
Introduction • 1