OmniSensor Temperature User Guide

Package Contents

• Sensor (1)
• Extension Cable (1)
• Insulation Gasket (5)

Setup Instructions

1. With your iOS device, download and launch the OmniTemp app from the iTunes Store.
2. Plug the sensor into your device's audio jack.
3. Alternatively, you can plug in the sensor into the extension cable and plug the other end of cable into audio jack.
4. For proper operation of the sensor, please make sure in the iPhone or iPad Settings that Settings->Music->EQ is OFF and Settings->Music->Volume Limit is set to MAXIMUM and then OFF.

Sensor Accuracy

Because the OmniTemp sensor is made of metal, it will exchange heat with your iOS device if plugged directly into the audio jack. With the included extension cable, you can thermally insulate the sensor from the iOS device to accurately measure the ambient temperature. Due to the thermal mass of the cable, please allow a few minutes to adjust to the surrounding temperature.

Special Note for users using OMNITEMP for NASA's Temperature Change during Totality project

Adding an air circulation device such as a fan to blow air at the sensor facilitates heat exchange with the ambient air and makes the sensor more sensitive to temperature change. However, please make sure the fan is at a reasonable distance from the sensor or you will impact the temperature reading due to the heat generated by the fan motor.

Here are some additional tips to improve sensor accuracy:

• Use the extension cable for accurate temperature measurement.
• Do not submerse the sensor or extension cable in water or any other liquid.
• If you must use the sensor for measuring the temperature of a liquid, or any electrically conductive surface, please use an electrically insulating medium, such as a finger cot or a thermometer probe cover, to prevent the liquid from damaging the sensor.
• Some combination of chargers, devices, and battery conditions cause injection of too much noise. If you see erratic readings, disconnect the charger during temperature measurement.
• Avoid directly touching the sensor as it impacts the accuracy of reading.
• The audio jack of an iOS device is a very delicate piece of hardware. Please insert and remove the sensor and extension cable very gently to avoid damaging the audio jack.
• The temperature reading may show TOO HOT or TOO COLD in normal room temperature if you have been using the audio jack of your device extensively. Should this happen, please attach one of the 5 provided thin clear gaskets to the connector (plug) of the OmniTemp sensor or the extension cable before plugging it into the audio jack of the device. Use a drop of glue to hold the gasket in place and prevent losing it. Please make sure you do not put any glue on the sensor or cable connector that inserts into the iOS device.

Sensor Calibration

OmniTemp sensors are carefully designed to meet strict specifications, but you can calibrate your sensor to make it even more accurate, up to +/- 0.1 degrees Celsius. There are two modes for user calibration: single point calibration and dual point calibration.

Single Point Calibration

If you have access to one known, stable temperature source, you can use this method to eliminate OmniTemp offset errors at this known temperature. Please note that this known, or reference, temperature must be in the normal operating range of OmniTemp. To use single point calibration, follow these steps:

1. Start the App.
2. Tap the settings at the lower right corner of screen.
3. On the Settings page, tap on Calibrate Manually.
4. On the Calibration page, choose Single Point.
5. Connect OmniTemp to the extension cable and plug the other end of cable into audio jack of the device.
6. Place the sensor in the reference temperature chamber. Liquids are allowed only if you have the necessary tools to prevent it from coming into contact with the sensor or cable.
7. Allow a couple of minutes until the Measured value stabilizes and does not change anymore.
8. Tap the box under REFERENCE and enter the known reference temperature.
9. Tap Set under Measured.
10. Tap on Save on the top right corner.
11. Tap on Done on the lower right corner.
12. Now the reading should match your reference temperature.

The offset value is applied to all temperature readings.

Dual Point Calibration

If you have access to two known, stable temperature sources, you can use this method to eliminate OmniTemp offset error reading at these known temperatures and apply a weighted offset to temperatures in between. We recommend that the two known temperatures be at least two degrees Celsius apart. To use dual point calibration, follow these steps:

1. Start the app.
2. Tap the settings (gear icon) at the lower right corner of screen.
3. On the Settings page, tap on Calibrate Manually.
4. On the Calibration page, choose Dual Point.
5. Connect OmniTemp to the extension cable and plug the other end of cable into audio jack of the device.
6. Place the sensor in the low reference temperature chamber (the lower of the two known temperature sources). Liquids are allowed only if you have the necessary tools to prevent it from coming into contact with the sensor or cable.
7. Allow a couple of minutes until the Measured value stabilizes and does not change anymore.
8. Enter the value of Lower Reference Value.
9. Tap Set under Measured in front of Low.
10. Repeat steps 6, 7, 8 and 9 above for a high reference temperature.
11. Tap on Save on the top right corner.
12. Tap on Done on the lower right corner.
13. Now the reading should match your corresponding reference temperature when you place the sensor in each chamber.

The offset values at Reference Temperatures are applied to all temperature below and above Low and High Reference temperatures respectively.

Notifications

The OmniTemp app allows you to set notifications, or alerts, to let you know when the temperature rises above or falls below certain values. To set these notifications, tap the Settings on the lower right corner of the app. Enter the desired values for one or both alerts, then tap on Done.

Data Logging

OmniTemp can log its temperature readings to a file stored on your device. To enable logging, go to the OmniTemp settings and turn on “Save data to file".  When enabled, this option will record about 15 temperature readings per minute. Enable logging only when you need it to avoid taking up unnecessary storage on your device.

To delete the log, tap the Clear button.      

To include your current GPS coordinates in the log, turn on the  “Include location”  option found in the Logging section of the OmniTemp settings.

The log file is formatted as comma-separated values (CSV), where each row corresponds to a single temperature reading and the columns are as follows:

Column 1: Date and time of the reading (format: yyyy-MM-dd HH:mm)

Column 2: Temperature reading (in Celsius)

Column 3: Location in degrees latitude (if "Include location" is enabled)

Column 4: Location in degrees longitude (if "Include location" is enabled)

To retrieve the log, plug in your device to a computer and launch iTunes. Open the settings page for your device and go to the Apps settings. Look for OmniTemp under the File Sharing section and click it. You can then drag-and-drop a copy of the log file (temperatures.csv) to your computer.

Feedback

The Settings screen at the bottom right corner of the app allows you to provide feedback to us. We care about your opinion and appreciate getting feedback on how we can improve.