473 Dew Point Hygrometer

  • Highly precise chilled mirror dew point technology
  • Cable mounted dew point and temperature measurement
  • Aspirated and direct insertion measuring heads
  • Barometric pressure measurement options
  • Digital and analogue interfaces
  • User verifiable calibration
MBW 473


Highly Precise Chilled Mirror Dew Point Technology

Chilled mirror condensation technology provides highly precise, stable and repeatable results. Water vapor condenses onto a temperature controlled highly polished mirror surface and this ‘dew point’ is detected with advanced optical electronics. Since dew point is specific to water vapor concentration and not temperature dependent, measurement precision is consistent across the full application range including high temperature and humidity conditions in climatic test chambers.
MBW chilled mirror hygrometers have a typical service life of more than 15 years thanks to the use of high quality materials and Swiss precision engineering. The high quality platinum resistance thermometer (PRT) element embedded within the mirror ensures excellent calibration stability. With precise measurements for dew point and temperature together with stability and long service life, MBW chilled mirrors are used by national standards and accredited laboratories worldwide. The 473 transfers reference standard performance into applications such as climatic chamber validation, relative humidity calibrators and a wide range of industrial processes.

Intuitive User Interface

The 473 features a 5.7” color touch screen with a high contrast ratio and wide viewing angle for clear and easy readability. Using the on-screen buttons and menus, each line of the instrument display can be configured for a variety of humidity, moisture, temperature and pressure parameters that may be viewed in the units of choice. These parameters can be displayed either numerically or graphically with user-configurable axes enabling measurement trends and stability to be confirmed without the need for external data acquisition or display hardware.

Flexible Measurement Options

The 473 is available with different measuring heads together with temperature and
pressure sensor options to meet the requirements of a wide range of applications.

SH2 Measuring Head

The SH2 is a flow-through dew point measuring head with a two-stage Peltier element for mirror temperature control. It includes a variable speed fan that maintains a consistent airflow across the mirror. Alternatively, with the fan removed, the SH2 head can also connect to applications using tubing and standard 6 mm fittings. It is also supplied complete with a calibrated temperature probe with 0.5 m and 3 m cables for connection to either the measuring head or the 473 back panel.

Typical SH2 applications include climatic chamber validation, humidity generators and in-situ calibration projects.

SH2 Measuring Head

RP2 Measuring Head

The RP2 dew point measuring head has a two-stage Peltier element in a compact probe format and includes a connection for temperature measurement. It is supplied as standard with a calibrated head mounted Pt100 probe and an extension cable to enable optimum placement in working volumes.

RP2 is suitable for direct insertion into applications with moving air such as relative humidity generators, climatic chambers, manufacturing processes and air ducts.

RP2 Measuring Head

Precise Temperature Measurement

The 473 is supplied with a 4-wire PT100 platinum resistance thermometer (PRT) for precise temperature measurement and to enable calculation of relative humidity. The temperature probe supplied can be connected directly to the measuring head, or by cable to the 473 back panel. Wider temperature measurement ranges and alternative probe configurations are available on request.

MBW 473 thermometer

Integrated Pressure Measurement

The pressure measurement option enables the 473 to compensate for pressure variations at the point of measurement to enable the lowest possible measurement uncertainties.
Standard and high precision pressure measurement can be specified; with precise dew point and temperature measurement, the 473 is suitable for use as a transfer standard for all three parameters in applications such as weather stations and calibration laboratories.

MBW 473 barometer

Convenient Calibration Check

Users can easily check the 473 system’s stability at any time using the built-in ice test function. This automated test procedure allows the user to confirm that ice on the mirror melts at 0 °C and verifies the stability of the mirror temperature measurement system.

It can be supplied with certificate of factory (MBW Calibration Ltd.) calibration according to ISO17025 standard in points: -20, 0, 35, 70 °C Dew Point, 5, 25, 50 °C Temperature.

Technical data

Measuring Ranges: Frost/Dew Point: -20…+70 °C (473-RP2)
-30…+70 °C (473-SH2)
Measuring Ranges: Relative humidity:  5 ... 100 %
Measuring Ranges:Temperature
-20...+80 °C (head mount PRT)
-50...+100 °C (cable mount PRT)
Accuracy: Frost/Dew point ≤ +/- 0.1 °C (in range -20…70 °C)
+/- 0.2 °C (out of range)
Accuracy: Temperature
+/- 0,1 °C
Reproducibility: Frost/Dew Point +/- 0,1 °C
Reproducibility: Temperature
+/- 0,05 °C
Digital I/O
Thermoelectric mirror cooling 2-stage with typically 50 °C depression at 20 °C ambient
Gas connections: 6 mm Swagelok (SH2 only)
Optional: Internal barometric pressure sensor 0.1% or 0.01% accuracy,
range 700…1200 mbar
Optional: Analog output
User programmable, 2x 4…20 mA or 0…10 V
Power supply: 100…120 VAC / 200…240 VAC, 50/60 Hz,
Power consumption: 100 Watt, autoswitching
Operating conditions: 0…40 °C, 90 %rh non-condensing (Instrument);
-20…80 °C, 99 %rh non-condensing (Measuring head)
Weight 5 kg
Dimensions: 265 x 155 x 265 mm

MBW Callibration Ltd. reserve the right to change design or technical data without notice.

MBW Calibration Ltd.
Seminarstrasse 57
CH-5430 Wettingen