Measuring Current, Voltage and Room Temperature, Humidity

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Joined: Tue Dec 08, 2020 2:57 am

Measuring Current, Voltage and Room Temperature, Humidity

Post by PatrickCF »


I am working on a project and try to record the running voltage and current of a HVAC unit while the Room temperature and humidity levels are also recorded for review.

As I am searching, I am guessing the PicoLog CM3 Current Data Logger will be the best option for Current, Voltage Measurement, on the other hand, I was not able to decide which product would be the best to measure and record the data on temperature and humidity level.

There are some options I have checked:

TC-08 Thermocouple Data Logger - Seems was not able to measure humidity level
DrDAQ humidity sensor - Not sure if it is the best option to work with CM3
EL005 Enviromon Data Logger - Seems this model is dis-continued?

Thank you for any support.

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Joined: Mon Aug 11, 2014 11:14 am

Re: Measuring Current, Voltage and Room Temperature, Humidity

Post by Gerry »

Hi Patrick,

The DrDaq with its DD101 humidity sensor is the most straightforward option for measuring temperature and humidity with inputs that detect the sensors and provide automatic scaling.

The CM3 is great for voltage and current monitoring as it automatically converts the values to RMS. So if you are only interested in Monitoring Single Phase rms voltage and current, in real time, then the CM3 will fit your requirement.
However, if you want to calculate Real (or True) Power as opposed to Apparent power (which is what you will get from rms voltage multiplied by rms current) then you will need the power factor (from the phase difference) so you would need to log the AC current and voltage. So, if you are powering a single phase HVAC unit you could use the scope input and spare input of the DrDaq to capture voltage and current.
If the HVAC is 3-phase, then things get a bit more complicated, for instance, with a balanced load you could use a 4 channel PicoScope (which can also be controlled by PicoLog 6 software, for long period logging) such as our PicoScope 4444, using the 4 wattmeter method of measurement. Ultimately, if you need to measure, more than 4 voltages and currents, you would need to use our 8-channel, PicoScope 4824.

(Note that with the current and voltage measurement you would need to be using a suitable Voltage Probe And Current Clamp depending upon where you are performing the measurement and also upon what the magnitude of the supply voltages and currents are. Note also, that although you could use a lower cost Scope for 4 channel measurements, the PicoScope 4444 would be more cost-effective for measuring 3 mains supply-level voltages, because it would enable you to use low cost Probes for the measurements.)


Technical Specialist

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