Contact Us

Phone: 1-888-NAGIOS-1

Nagios Conference

Register for Nagios World Conference 2014

Nagios Live Webinars

Let our experts show you how Nagios can help your organization.

Connect With Us

Facebook Twitter YouTube LinkedIn

ESensors Websensor EM01B

| Print |  E-mail
Bookmark and Share

esensors_logo_smallWant to monitor the environmental conditions in your server room or wiring closet? Need something that can be monitored with Nagios®? The Websensor EM01B from ESensors fits the bill.


Worldwide Ordering Information

To order, or obtain more information:

European customers contact SENSORMETRIx for ordering information.
Customers in the U.S. and elsewhere should contact ESensors for ordering information.


em01b_mediumThe Websensor EM01B connects directly to your Ethernet network via a 10/100 Mbps switch or hub port. It provides monitoring for temperature, illumination (light level) and relative humidity, and is ideal for monitoring environmental conditions in server rooms and wiring closets. It is capable of measuring DC voltages, which allows you to check battery supply voltages of UPS units or renewable energy sources. The new thermistor interface allows you to interface external special use sensors, such as liquid temperature measurement and the new contact closure detection allows you to detect door open conditions (for security purposes) or configure equipment start-up and shut-down conditions.

The Websensor by Esensors enables you to monitor temperature, humidity and illumination in one location. The Websensor comes in 3 versions:

EM01B-STD features contact closure monitoring. EM01B-VLT features DC voltage monitoring. EM01B-THM features Thermistor add-on monitoring.



  • Attaches to a standard 10/100 Mbps Ethernet port
  • Sensor data is transmitted by internal web server
  • Uses the Ethernet port to configure Websensor IP address New!
  • Internal sensors for temperature, relative humidity, and illumination
  • Measures voltage (0 to 18 VDC)New!
  • Detects contact closure New!
  • Thermistor interface for external/optional temperature sensing New!
  • Optional ESBus for external sensors (power line monitoring, etc.)
  • Programmable email alerts to notify user of MIN/MAX set-point violations in temperature, relative humidity and illumination

Detailed information on the EM01B can be found here.


An Esensors Esbus is now available on the EM01B to allow for support of other Websensor peripherals:

  • ES11 - Moisture Sensor (detects moisture on floor as precursor to potential flood conditions)
  • ES01 - Display: 2 line, 16 characters per line display
  • ES06 - Relay Switch Module: Optically isolated inputs/dry contact outputs

More information on addons for the EM01B can be found here.


  • Temperature: -40C (-40F) to +123.8C (254.9F)
  • Illumination: 0 to 1000 Lux
  • Relative Humidity: 0 to 100% RH
  • Temperature: +/- 0.2C @ 25C
  • Illumination: Uncalibrated
  • Relative Humidity: +/- 3%
DC Voltage Measurement:
  • 0 to +18 VDC (Center pin of connector is (+)positive.)
Thermistor Interface:
  • Customer supplied specifications resistance at 25C required to determine correct components.


Information on integrating the EM01B with various Open Source monitoring packages (i.e. Nagios and MRTG) can be found on Nagios Exchange.


Purchasing Information

Nagios users can get up to a $15* discount of the prices listed below when purchasing the EM01B! For price quotations, you must send email to to get discounted pricing or you may order online at Esensors Web Store and enter coupon code NAGIOS15 when checking out.

*Discount valid for customers in the U.S.A. only.

European customers should contact SENSORMETRIx:

Sensors Division Sales: +44 (0)118 976 9000
Fax: +44 (0) 118 976 9020 / 9070

Retail pricing is as follows, with the $15 discount available for all 3 models:

*EM01B-STN* - $520 USD
*EM01B-VLT* - $535 USD
*EM01B-THM* - $540 USD

All Websensors include an Ethernet straight cable and wall power supply.

Each order will also receive one free Software & Documentation Package which includes a printed manual, CD and crossover cable regardless of quantity ordered.