Building Intelligence

Embedded Moisture Sensor (EMS)

Sensors are embedded in gypsum or concrete to detect relative moisture content through capillary absorption.

Overview
Specs
Mounting

Overview

General Description

The Embedded Moisture Sensor (EMS) is an indirect moisture measurement device also known as a Duff Gauge, Surrogate Moisture Sensor or Wood Resistance Humidity Sensor.

Use for indirect measurement of moisture levels in materials unsuitable for standard measurement techniques, such as gypsum, concrete, masonry, insulation or other such substrates. Sensors comprise gravimetrically calibrated, temperature compensated Helmlock wood elements with known moisture content related characteristics. Sensors are embedded in the material to be monitored to obtain the relative moisture level of the surrounding area through capillary absorption.

Sensor readings are acquired by the WiDAQ, a precision data acquisition device, and transmitted to the Building Intelligence Gateway where sensor specific temperature compensated calibration curves are applied.

Two sensor grades are available. Commercial grade sensors use published a and b calibration values for the wood species used. Research grade sensors are individually calibrated to accurately relate gravimetric moisture content with electrical moisture content. Typical sensor elements are based on Western Hemlock, a hardwood with favourable characteristics.

Features

The EMS is available in both block and plug styles. The cylindrical plug sensor is suitable for monitoring stone, concrete, and masonry, where drilling a hole to the appropriate depth is the most practical access. The block style is suitable when a cut-out at the correct location is feasible, for example, in rigid insulation and gypsum sheathing. Further details and custom sizes are available on request.
Sealed and rugged design allows for deployment in harsh construction environments
Integrated temperature sensor used for temperature compensation and for reporting temperature sensor data.
Research grade EMS units are individually calibrated to produce a and b calibration constants for an accurate moisture content calculation. Formulae available upon request.

Specs

Electrical Charracteristics
Operating Voltage	2V to 12VDC
Resistance Mesurement Range	100 ohms to 1Gohm
Thermistor Measurement Range	-40°C to 125°C
Thermistor part number	Cantherm MF52C1104F4150
NTC Thermistor Beta Value	4150K
BiG/Analytics Sensor Config	Thermistor: MF52 (C) Moisture: Moisture (%)

Environmental
Operating Temperature	-40° to 50°C
Application Temperature	5°C to 50°C
Storage Temperature	-40° to 50°C
Storage Humidity	5% to 90% RH non-condensing