Cloud-based CO2 monitoring system for better air quality in COVID-19 situation

A cloud-based CO2 monitoring system was configured by OTM for air quality monitoring in the COVID-19 situation.


The following two documents were followed in this application:

The CO2 level monitored is used as a proxy to justify the ventilation adequacy in the COVID-19 situation:

  • If the CO2 level is above 800 ppm, the ventilation may not be sufficient;
  • If the CO2 level is above 1100 ppm, the ventilation level is insufficient according to Singapore Standard SS554:2016.


Delta Ohm HD50 web data logger was used for this application. The model selected was HD50G1NBTV. It has built-in probes for CO2, temperature, and humidity measurement.

The instrument can meet all requirements specified by NEA/BCA. It also automatically uploads the data to Delta Ohm cloud via ethernet or wifi. Shown below are the results displayed in the cloud portal.

The instrument was pre-configured by OTM. The end user just needed to do the last-step mechanical mounting. All authorized users can access the results at the cloud portal with a browser and it is very convenient for facility managers who are busy with many things.

WBGT measurement with natural wet bulb temperature probe

Related instruments Temperature & humidity, Thermal comfort

An earlier post showed WBGT measurement with a combined temperature and humidity probe. With this configuration, the natural wet bulb temperature is calculated.

Shown below is a configuration of the same HD32.3TC instrument with a wet bulb temperature probe. In this case, the wet bulb temperature is directly measured, in compliance to ISO 7243.

HD32.3TC can be configured in various ways for thermal comfort, indoor air quality and microclimate analysis. Please refer to the data sheet of HD32.3TC for more details.

Full-size solar panel daylight reflectance test

Related services Daylight reflectance

We are able to test the daylight reflectance of full-size solar panels. Shown below is an example.

All typical commercial solar panels can be tested, including panels greater than 1.2 m x 2.4 m in size. The results reported are the same as our standard daylight reflectance testing service (sample report). Due to the extra effort in handling such large and heavy samples, some large-size sample surcharge is applicable.

Import Optics user database into LBNL WINDOW

Related services Glass optical & thermal properties

We have a post on how to import user IGDB format file into LBNL optics. The next step is to import the user database created into LBNL WINDOW for further calculations. Please refer to the steps below for the operations.

Step 1. Set the user database as the optical data source

In the “File” -> “Preference” -> “Optical Data” tab, browse the Optics user database file and set it as the optical data source, as shown below.

Step 2. Import glass optical data from Optics user database

In the glass library (“Libraries” -> “Glass”), click “Import” (in the “List” view). In the pop-up window, set the format as “IGDB or Optics User Database”, as shown below. The optical data entries in the Optics user database can then be imported in the next pop-up window.

Our instrument: heat flow meter

We are a Singapore-based third-party test laboratory, providing lab test services of material optical & thermal properties. We use Thermtest HFM-100 heat flow meter, with the following key information.

Thermtest HFM-100 heat flow meter

Key specifications:

  • Preferred sample size: 300 mm × 300 mm
  • Maximum sample thickness: 100 mm
  • Plate temperature range: -20 – 70 °C
  • With high thermal conductivity kit

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