There are three different triggering Modes available:

• Manual Triggering: Logging starts after the user toggles the logger's manual trigger switch, with an optional delay.
• Triggering on Disconnect from PC: Logging begins immediately or after a specified delay once the logger is removed from the Logger Dock.
• Temperature Thresholds (Start/Stop Levels): More advanced features that allow logging to start when the measured temperature rises above a specified value and stop when it falls below another. This can inhibit logging until the logger is actually inside the oven, conserving memory.

A typical SL4000-Series Temperature Logging System includes several core components:

• SL4000 Logger Unit: This is the high-temperature data logger capable of passing through curing ovens.
• Logger Dock (PowerDock™): Used for charging the Logger Unit, uploading logging parameters, and downloading logged temperature data to a PC. It also aids in cooling the logger.
• Temperature Patch Probe Sets: These consist of a central plug with up to seven thermocouple probe cables of varying lengths, each ending in a thermocouple junction for temperature measurement.
• Thermal Jackets: Such as the SmartCan™ Thermal Jacket or SmartSheet™ Thermal Jacket, these are heat-resistant containers that protect the Logger Unit from high temperatures, allowing it to withstand hotter environments for longer durations. They are crucial for applications with longer transit times in ovens like IBO/OBO or wicket ovens, but typically not needed for fast-transit pin ovens.
• Hexagon™ Software: Sencon's proprietary data logging and analysis software, used for programming the logger, downloading data, and comprehensive data analysis and graphical display of curing profiles.

Before a logging run, the SL4000 Logger unit needs to be prepared using the Hexagon analysis software. The logger is placed in the Logger Dock to charge its high-temperature lithium-ion battery. A full charge takes approximately 6 hours and can power the logger for up to 230 hours at a medium sampling rate (1 Hz) or 60 hours at a fast rate (10 Hz). A 10-minute quick charge provides about 3% battery life, sufficient for an additional 5 hours at 1 Hz or 50 minutes at 10 Hz.

Logging parameters such as sampling rate, triggering mode and active channels are uploaded from Hexagon to the logger. Calibration data is stored locally on the logger, simplifying setup.

The logger, is placed within a thermal jacket depending on the oven type, is attached to an "instrumented" can or sheet assemblage. This involves attaching the patch probes to specific points on the can/sheet using high-temperature tape and heat sink compound to ensure good thermal contact.

Hexagon™ is Sencon’s proprietary data logging and analysis software, serving as the central control hub for Sencon's Temperature Logger Systems. Hexagon is used to program and initialize the Logger Unit. This involves setting logging parameters such as enabling or disabling individual thermocouple probes, choosing a sampling rate which determines how frequently temperature readings are taken and defining when logging starts (manual switch, on disconnect from dock, or temperature thresholds).

After a logging run, Hexagon downloads the logged temperature data from the Logger unit and provides powerful data analysis and graphical display capabilities, allowing users to view standard temperature-over-time graphs, illustrate temperature gradients for each burner in an oven and perform trend monitoring and statistical process control (SPC) functions.

Patch probes are critical for accurate temperature measurement at the surface of cans or metal sheets. The procedure for attachment emphasizes good thermal contact and proper insulation:

• Probe Preparation: Most probes come with a self-adhesive patch. If not, a patch is cut from high-temperature self-adhesive tape and applied over the thermocouple junction and bare wires.
• Heat Sink Compound: A small dab of heat sink compound (less than a pinhead) is applied to the flattened thermocouple junction before sticking the probe. This is crucial for rapid heat transfer from the can/sheet to the thermocouple, preventing lagging readings, especially in fast-transit ovens.
• Placement and Adhesion: The probe is stuck firmly to the desired location on the can or sheet using the self-adhesive patch. Rubbing and pressing it down ensures good thermal contact. Loose cables are taped down to prevent snagging inside the oven.
• Insulation (for bare metal): If the can or sheet is bare, unlacquered metal, squares of high-temperature self-adhesive tape are stuck below the probe head to insulate the thermocouple arms, preventing them from shorting through the metal. The thermocouple junction is slightly offset to ensure it still touches the metal.
• Air Temperature (Optional): One probe can be left unfixed, approximately one centimeter above the metal surface, to log the air temperature within the oven.

The SL4000 Logger Unit has specific thermal limits to prevent damage, especially to its internal lithium-ion battery. Exceeding these limits risks battery damage, and in extreme cases, fire. The durations below assume the logger starts at ambient temperature. Users are responsible for checking that their specific oven's temperature and transit time will not exceed these thermal limits.

Bare Logger (without Thermal Jacket):

• Up to 2 ½ minutes at 200°C (392°F)
• Up to 3 minutes at 150°C (302°F)
• Up to 8 minutes at 100°C (212°F) This setup is typically sufficient for pin ovens due to their very fast transit times (seconds).

• Up to 15 minutes at 350°C (662°F)
• Up to 30 minutes at 150°C (302°F)
• Up to 60 minutes at 110°C (230°F)

• Similar or identical thermal limits to the SmartCan™ jacket, designed for wicket (sheet) ovens.

The SL4000 offers various sampling rates to optimize data logging and memory usage. The choice of sampling rate defines how often temperature readings are taken and impacts logging duration; faster rates fill memory quicker. Fast rates are recommended for quick-transit ovens (e.g., pin ovens), while slower rates suit longer processes (e.g., IBO/OBO ovens).

• Slow (0.1 Hz): One reading every 10 seconds
• Medium (1 Hz): One reading per second
• Fast (10 Hz): Ten readings per second.

Annual calibration is important to maintain the accuracy of the SL4000 Oven Logger. The logger is calibrated to UKAS standards before being shipped, and its calibration data is stored directly on the logger itself, eliminating the need for separate calibration files. The SL4000 now offers the convenience of on-site calibration during an annual service visit, removing the need to return to Sencon for calibration.

During the calibration process, the logger's readings are compared to a reference standard. If they align, a new calibration certificate is issued. If there is a discrepancy during on-site calibration, the logger needs to be sent back to Sencon for full recalibration and adjustment. It is recommended that the logger is sent back to Sencon every three years for a comprehensive recalibration and performance validation.

The SL4000 Logger unit contains a high-temperature, rechargeable lithium-ion battery. It takes approximately 6 hours to fully charge the logger battery from zero charge. A 10-minute quick charge provides about 3% battery life, sufficient for 5 hours at 1 Hz or 50 minutes at 10 Hz. Charging is inhibited if the internal temperature exceeds 40°C as a safety feature.