A labeled data logger is located on the left of the image. To the right is a current sensor used with the logger for data collection.

Using Data Loggers

Data loggers are used to monitor electrical current, temperature and other process variables in plant operation. Motors, lighting, and thermocouple activity can be recorded and analyzed using data loggers.

Data loggers can vary in the quantity of data it can store from one session. The OSU IAC uses data loggers that can collect up to 32,520 data points.

These data loggers are typically sent to the facility at two weeks prior to the assessment date. The data loggers can be placed on main pieces of equipment ahead of time, so one week's worth data could be recorded before the assessment.

Alternatively, data loggers can be installed during the assessment. A shipping case would then be left with the facility so they can be sent back one week later.  

Picking a Sensor

Current transducers (CTs) are available in 20, 50, 100, 200, or 600 Amps. Lower ranges provide more precision. 

**Transducers should only be attached around a single phase of three phase equipment. Typically this will be one wire, but on occasion each phase may require two wires for high amperage applications.**

Setting up Data Logger

  1. Connect data logger to a computer that has the associated data logger program installed using the appropriate cable. In the case of OSU IAC, use HOBOware.
  2. Launch the data logger program and check the battery charge level. 
  3. Label the data logger appropriately (name and size of motor).
  4. Choose settings for recording based on the desired resolution and duration.
    • Normally data loggers are programmed for a week.
  5. The data logger can be launched either immediately or with a delay depending on when data collection is desired.
    • You should typically always set up the data logger with a delay rather than starting immediately. 
  6. Chose a properly sized CT.

Installing a Data Logger

  1. If a sensor is to be used, have a facility personnel/electrician place it where the measurement is to be taken.

Retrieval of Data Logger

  1. Retrieve the data logger when data collection period has elapsed. This may require the client to ship data loggers, or analysts to physically collect them.

Offloading Data

  1. Connect the data logger to a computer with the associated data logger program using the appropriate cable.
  2. Readout the logger and save the data.

Analyzing Data

  1. Data can be exported into an Microsoft Excel spreadsheet. Excel can graph up to 32,000 data points.
  2. Manipulate data as needed, such as delete peak current draw from motor start ups.

*OSU analysts can perform the analysis using the Motor Analysis Tool. Instructions and details can be found on the Motor Analysis Template page.*