For installations such as water injection flow lines, leaks can be identified using the temperature difference between the surrounding seawater and any water leaking from the flowline. The flowline water temperature is normally above ambient seawater temperature.
Neptune has developed a differential temperature measurement technique that can detect very small temperature changes. The sensors comprise fast, high precision thermistors connected through the Neptune leak detection system to the ROV umbilical for onboard display and recording.
The temperature probes are designed for use with the 2 channel leak detection system and can be used simultaneously with a fluorometer or acoustic sensor connected to the second channel. Data are displayed graphically and recorded on the onboard PC.
The probes use the loggers gain control line to switch between two modes:
1. Direct temperature
2. Temperature gradient
In the direct mode the sensor will output the temperature in degrees Celsius. The valid temperature range is between -2ºC and 50ºC.
The temperature gradient mode detects rate of change of temperature, therefore a rapid change of temperature will show up as either a positive or negative peak in the data.
- Operating depth 2000m
- Calibrated temperature range -2ºC to 50ºC
- Accuracy ±1ºC
- Temperature Gradient range ±2deg/second
- Supply Voltage 12 – 36 vdc