101 Industrial Blvd Turners Falls MA 01376 +1 (413) 863-0200 sales@yesinc.com

DPT-2011 Single Stage Dew Point Transmitter

General Description

The DPT-2011 Single Stage Dew Point Transmitter uses the chilled mirror principle to determine the absolute humidity of any gas in terms of its dew- or frost-point temperature. It was specifically designed for laboratory, field and industrial process applications. The control electronics maintain the sensor mirror to the equilibrium point where a dew or frost layer is established on the mirror surface. A platinum resistance thermometer directly monitors the mirror temperature. Depending on the actual dew point, settling time from ambient may take a few seconds to one minute. A local digital display and analog and digital interfaces are provided.


Convenient front panel digital readout

4-20mA analog and RS-232 digital outputs

Rugged hard chromium mirror provides extra durability in industrial applications

Runs from a single 12 Vdc, 2.1A supply

LED indicates when mirror needs cleaning


Chilled mirror dew point hygrometers are used in industrial process-control and laboratory applications to ensure product quality, including:

Real time production process control of pharmaceutical, plate glass, paper, plastics

Production monitoring for dried foods and dry snack processing

Monitoring of storage environments and special purpose rooms such as museums, warehouses, computer and clean rooms

Manufacturing quality control for fabrication of sensitive electronic components such as semiconductors

Building HVAC or air quality monitoring

Mirror Access

A front-mounted threaded hole plug supports access to the chilled mirror for periodic cleaning. Sample gas typically passes through the system via a flow gauge and filter tubing connections. Flow rates from 0.5 to 1.0 standard cubic feet per hour (SCFH).

DPT-2011 Single Stage Dew Point Transmitter

User Interface

A front panel digital meter indicates the current dew point temperature. A pushbutton lets you rapidly check that the mirror is clean without having to open the sensing chamber for inspection. An LED indicates when cleaning is required. Both RS-232 serial and 4-20mA analog outputs are provided. The serial interface supports a graphical LabView™ application for MS-Windows9x/NT that permits you to view real time sensor data on a PC or Mac.

DPT-2011 cross section

DPT-2011 showing access location for mirror cleaning

Mechanical Interface

Dimensions in inches [cm]


Dew/frost point

40° C depression; @22°  C, dew/frost points can be measured to ≈ -18°  C


± 0.26° C


± 0.01° C


0-30 PSIG



Response time

35 seconds (typical)

Power Supply

+11 to +14 VDC, 2.1A

Gas contacts

Anodized aluminum, Viton, glass, chromium, diallyl phthalate

Output signals

10'/3 m cable 4-20mA anal, DB-9M RS232 (DTE) digital

Temperature regimes

-40° C to +50° C operating
-60° C to +60° C storage
(0-90% RH non-condensing)