CMDP-P Chilled Mirror Dew Point/ Temp. Transmitter
Pipe Mounted Chilled Mirror Hygrometer (Dewpoint only)
Supported Applications
The Omega CMDP Series is a family of low-cost chilled mirror dew point transmitters configured as duct, wall, pipe, or OEM units. The series utilizes primary measurement principles to provide stable, accurate, and repeatable measurements traceable to NIST.
Duct mounted applications (CMDP-D)
Wall mounted applications (CMDP-W, CMDPT-W)
Pipe mounted applications (CMDP-P)
Operating Conditions & Performance
The series operates within a process temperature range of -40°C to +60°C. Measurement capabilities include dew point from -20°C (@ 25°C) to 60°C (non-condensing), and down to -40°C when the sensor body is at 0°C. An optional air temperature probe supports measurements from -40°C to 120°C.
• Accuracy: ± 0.5°C for both dew point and temperature
• Repeatability: ± 0.05°C
• Resolution: 0.01 %
• Air Velocity: 50 to 900m/min
The unit requires a power supply of 24Vdc +/-3V @1.0A and has a pressure rating of 2 ATM (per data sheet) or 5 ATM (per manual). Wetted materials include Nickel, ultem, and anodized aluminum.
Configuration Options
The CMDP Series offers configurable mounting styles and measurement types. The series supports two 4-20mA outputs that are factory scaled for -20°C to 60°C unless specified on the purchase order. An RS232 communication connection is available via a 12-pin terminal block.
Mounting Configurations
• Duct mounted (CMDP-D)
• Wall mounted (CMDP-W, CMDPT-W)
• Pipe mounted (CMDP-P)
Sensor Options
An air temperature probe is available as an optional accessory for wall and OEM configurations. The probe connects via 4 Wire flying leads.
Key Product Differences
The series distinguishes models by mounting location and measurement capability:
• CMDP-D: Duct mounted chilled mirror hygrometer (dew point only)
• CMDP-W: Wall mounted chilled mirror hygrometer (dew point only)
• CMDPT-W: Wall mount chilled mirror hygrometer with dew point/air temperature
• CMDP-P: Pipe mounted chilled mirror hygrometer (dew point only)
Maintenance involves cleaning the mirror using a wetted cotton swab to restore normal operation. Settable service cycles are available for balancing and cleaning.
| Accuracy | ± 0.5 °C (± 0.9 °F) |
| Additional Features 1 | NIST Traceable |
| Air Velocity, Max | 900 m/mn |
| Data Interface | RS232 |
| Dew Point Temperature, Max | 60 °C |
| Dew Point Temperature, Min | -20 °C |
| Dew Point Temperature Note | Dew Point -20°C (@ 25°C) to 60°C (non-condensing) Dew Point -40°C (@ 0°C) Temperature probe: (optional) - 40°C to 120°C |
| Electrical Output | 4 to 20 mA |
| Operating Temperature, Max | 120 °C |
| Operating Temperature, Min | -40 °C |
| Output Detail | (2) 4 to 20mA output at 24Vdc (configurable). Default settings: - 20°C to 60°C (unless specified on purchase order. Analog Output scaled range Dew Point (4- 20mA) User Selectable: 2) 4-20mA -24 Vdc (configurable) Factory set-both outputs, -20C to 60C (unless specified on order) |
| Pressure Limits | Up to 29 psi |
| Measurement Pressure, Min | 0 psi |
| Repeatability | ± 0.05°C |
| Resolution | 0.0001 |
| Series ID | CMDP-Series |
| Supply Power Type | DC |
| Supply Voltage | 24 Vdc |
| Temperature Measurement, Max | 60 °C |
| Temperature Measurement, Min | -40 °C |
| Weight | 5 lb |