Detcon DM-100 - Manual (Page 5)

Model DM-100
DM-100 Instruction Manual Rev. 3.3 Page 1 of 40
1. Introduction
1.1 Description
Detcon Model DM-100 toxic gas and O
2
deficiency sensors are non-intrusive 4-20mA loop powered sensors
designed to detect and monitor a wide range of toxic gases in the air. Ranges of detection for toxic gases are 0-
1ppm up to 0-10,000ppm; typical ranges of detection are 0-10ppm, 0-25ppm, 0-50ppm and 0-100ppm. Ranges
for O
2
deficiency are 0-1% up to 0-25% by volume.
The basic sensor assembly consists of an electrochemical fuel cell mounted in Intrinsically Safe stainless steel
housing and includes a Splash Guard Cal Adapter. Optionally, the sensor can be installed on an explosion
proof junction box with a Model 100 Terminal Board and may include a Model 100 Loop Powered LED
display. Other options are available, contact Detcon for more information.
DETCON, INC.
H2S 100 PPM
DM-100
Model 100
Figure 1 Sensor Assembly with Optional J-Box and LED Display
Electrochemical Sensor Technology
The DM-100 toxic gas sensors are based on electrochemical cells. Each cell consists of three electrodes
embedded in an electrolyte solution all housed beneath a diffusion membrane. Sensitivity to specific target
gases is achieved by varying composition of any combination of the sensor components. Good specificity is
achieved in each sensor type. The cells are diffusion limited via small capillary barriers resulting in a long
service life of up to three or more years. The electrochemical cell is packaged as a field replaceable plug-in
sensor.
Figure 2 Construction of Electrochemical Toxic Sensor