Handheld data logger for UVC irradiance measurement

Related instruments Light & radiation

UVC disinfection is used in HVAC systems to eliminate germs and viruses, particularly in the current COVID-19 situation. UVC irradiance measurement is required for UVC radiation level control.

Shown below is a handheld data logger for UVC irradiance measurement, with the following components:

  • HD2102.2: handheld data logger for light and radiation measurement
  • LP471UVC: probe for UVC irradiance measurement

At the customer’s request, an ISO 17025 calibration certificate can be provided at an additional cost.

Wind speed & direction measurement with Delta Ohm HD53LS ultrasonic anemometer

Related instruments Weather stations, Wireless & web data loggers, Air speed & wind

Shown below is a wind speed and wind direction measurement system, with the following components:

  • HD53LS.S 2-axis ultrasonic anemometer with MODBUS-RTU output
  • HD35EDW-MB wireless data logger with MODBUS-RTU input

For this system, OTM also supplied a 2-meter-long stainless steel pole for mounting and wired/configured all instruments before delivery. The last step mechanical mounting was done by the end user. A USB dongle type base unit (HD35APD) was also included for manual downloading of monitoring data in a scheduled interval.

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

Related instruments Temperature & humidity, Wireless & web data loggers, Air quality sensors

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.

Weather monitoring with Delta OHM HDMCS-100 all-in-one weather station

Related instruments Weather stations

Shown below is a Delta OHM HDMCS-100 all-in-one weather station installed at a construction site for weather monitoring.

The instrument measures the following 6 quantities:

  • Wind speed
  • Wind direction
  • Temperature
  • Humidity
  • Pressure
  • Rainfall

The data are automatically uploaded to Delta OHM cloud via 4G. The end users can conveniently view the results with a web browser.

The initial hardware wiring and software configurations were performed by OTM and the end users just needed to do some simple last-step mechanical mounting.

HD2003 3-axis ultrasonic anemometer

Related instruments Weather stations, Wireless & web data loggers, Air speed & wind

Shown below is a Delta OHM HD2003 3-axis ultrasonic anemometer (undergoing testing in our office):

The instrument measures 3 velocity components (u, v, w velocity components) and 3 additional quantities (temperature, humidity, and barometric pressure), and calculates a number of derived quantities (wind speeds and directions, sonic temperature, and wind gust), as shown in the screen capture below:

In this application, the data collected by HD2003 is logged by Delta OHM HD35EDW-MB wireless data logger with MODBUS-RTU input.

KSJ MG6-F1 gloss meter

Related instruments KSJ gloss meters

For general applications, KSJ MG6-F gloss meter is recommended. Listed below are the key specifications:

  • Angle: single-angle (60°)
  • Range: 0 – 199.9
  • Resolution: 0.1 GU
  • Beam size: 10 mm × 20 mm

More information is available in the following documents:

For more details, please expand one of the blocks below.


The gloss meter uses 1 piece of AA-size battery. The typical battery life is around 58 hours (alkaline battery; without backlight and BlueTooth).

Basic operations

There are just 3 simple steps to perform gloss measurement:

  1. Power on
  2. Calibration
  3. Gloss measurement

1. Power on

Long press the “ON/OFF” button to switch on the gloss meter

2. Calibration

There is a calibration board in the base holder of the gloss meter (shown above). Mount the gloss meter to the base holder and buckle it properly.

Short press the “Calibration” button. While the “CA” symbol is flashing, short press the “Calibration” again. The “CA” symbol disappears and the gloss meter is calibrated.

3. Gloss measurement

Take out the gloss meter from its base plate. Attach the measurement port (at the bottom of the gloss meter) to the surface to be measured. The gloss result is displayed on the screen, without pressing any button.

Good practices

The following good practice practices are recommended:

  • Keep the calibration board and the lens in the measurement port clean.
  • Re-calibrate the gloss meter frequently.
Smartphone controlled gloss measurement

It is possible to perform online gloss measurement with a smartphone (both Android and iOS) via BlueTooth connection and store the gloss measurement results in the smartphone.

Refer to the user’s manual for the details.