HD35 Wireless Data Logger System

What it can log

HD35 data loggers are available for:

• Temperature and humidity
• Atmospheric and differential pressure
• Illuminance (lux) and UVA, UVB and UVC irradiance
• Carbon monoxide (CO) and carbon dioxide (CO2)
• Solar radiation and rainfall quantity
• Wind speed and direction
• Leaf wetness
• Soil volumetric water content
• Level
• WBGT index

Models that measure relative humidity and temperature also work out derived humidity quantities, which vary by model: dew point, wet bulb temperature, absolute humidity, mixing ratio and partial vapor pressure. External probes plug into the logger through an M12 connector or a screw terminal header, depending on the model, and some models come with built-in sensors.

Expanding the inputs

Loggers with terminal header inputs can take:

• Transmitters with 0÷20 or 4÷20 mA current output, or 0÷50 mV, 0÷1 V or 0÷10 V voltage output
• Pt100 / Pt1000 temperature sensors and K, J, T, N, E type thermocouples
• Sensors with a voltage-free contact output (switch counting) or a potentiometric output
• Sensors with RS485 MODBUS-RTU output

That opens the system up to countless other quantities beyond those listed above.

Where it is used

• Food services: refrigerated containers, cold storage, food production and carriage
• Health: storage of medicines, vaccines and blood; incubators and operating rooms
• Greenhouses and agricultural crops
• Environmental analysis: air quality, meteorology and hydrology
• Museums and document archives
• Transport of perishable and fragile goods
• Air conditioning
• Clean rooms
• Laboratories
• Industrial processes

System components

• HD35AP…: base unit
• HD35RE…: repeaters
• HD35ED…: data logger series
• HD35ED-ALM: remote alarm module

HD35AP… base unit. It links the system's data loggers, placed at the measurement sites, with the PC, and talks to the remote loggers wirelessly. When it is connected to the PC by USB, the PC's USB port powers it directly; without USB, it runs on its internal rechargeable battery or on the optional external power adapter. The HD35APW and HD35APG…/HD35AP3G… versions need the external adapter.

HD35RE… repeaters. They bridge the HD35AP… base unit and the remote HD35ED… loggers, extending the communication distance between them; several repeaters can be chained between a logger and the base unit to reach even further.

HD35ED… data loggers. These are the remote units wired to the measuring probes. Installed in the areas to be monitored, they run on a long-lasting internal battery (not rechargeable), store readings in internal memory and send them to the base unit automatically at regular intervals or when the user asks. They come with or without LCD; the LCD versions also show the readings and the RF signal quality on site and can be configured from the front keypad.

HD35ED-ALM remote alarm module. Its relay outputs drive signaling devices (sirens, flashing lights, etc.) or actuators.

Why wireless helps

A system can hold up to 255 devices, counting the base unit and any repeaters, and each one has its own unique address. With no cables to run, installation is simple and fast, material and labour costs drop considerably, and components can be moved whenever needed. There is also no need to take a logger down or visit the site to download its data to the PC.