Pre-Setup Requirements
Before starting your monitoring, power on the EVM-7 by pressing and holding the power button [00:42]. Ensure the unit has been properly calibrated for the specific gases you intend to measure.
Step 1: Data Logging Configuration
Setting up your logging parameters is essential for capturing the right data over time:
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Logging Interval: Access the setup menu and set how often the device records a data point. Use the arrow keys to adjust this value [01:04].
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Averaging: Ensure the display averaging time is equal to or less than your logging interval so the real-time display remains consistent with your logs [01:12].
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Select Metrics: Enable the specific values you want to record, such as minimum, maximum, average, and short-term exposure levels (STEL) [01:18].
Step 2: Date, Time, and Units
To ensure your reports are accurate and legally defensible, verify the internal clock and measurement units:
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Timestamping: Adjust the time and date so every data log is correctly stamped [01:38].
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Unit Selection: Choose between Celsius or Fahrenheit for temperature [02:02]. For particulates, select either milligrams or micrograms per cubic meter [02:18].
Step 3: Enabling Sensors
The EVM-7 allows you to toggle specific sensors to save battery or focus on specific pollutants:
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Particulate Sensor: Enter the particulate menu to enable the internal pump and sensor [02:39].
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PID Sensor (VOCs): Enable the Photoionization Detector (PID) and adjust the correction factor if you are sampling a gas other than isobutylene [02:52].
Step 4: Running the Study
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Starting: Press the Run/Stop button in the bottom left corner. If the particulate sensor is active, you will hear the internal pump engage immediately [04:11].
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Navigating Readings: Use the left and right arrow keys to cycle through real-time screens for particulates, gas levels, climate data, and a composite summary screen [03:26].
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Stopping: Once your study is complete, press the Stop button. All logged data is automatically saved to the instrument's internal memory for download [04:41].
