Unsure if IR sensor has issues

I’ve been roasting quite a few batches, and finally just noticed that my IBTS curve seems quite a lot different from the posts I’ve seen here on this forum!

Just wondering if anyone can shed light if there might be an issue with my IBTS, or if I’m doing something wrong… Please let me know if I need to provide more info!

I generally do 800g batches and every single roast has an IBTS curve like this. That said my coffee has been coming out fine and I’m still happy with it. Roasting on a v1 Bullet.

you sure you have an IBTS probe? Read here Infrared Bean Temperature Sensor: Introduction and Quick Guide | by Aillio | Medium

Your roast profile is about what you should expect from a V1. The IR sensor is in the faceplate behind a germanium window. Your V1 bullet doesn’t have the IBTS which was introduced with V1.5 & V2. Many of the earlier V1s have been upgraded to the IBTS thru an upgrade kit available from Aillio.

On V1.5 & V2 Bullets, the IBTS is mounted behind a rubber view port in the faceplate area where the control panel pedestal attaches. The IBTS is not a probe; it’s an IR sensor which views IR radiated from the drum or from the beans via the view port. That view port is a black rubber molding with a hole in the approximate center with a fan blowing air from the pedestal air inlets out through that center hole in the view port. That air is intended cool the snesor and to keep out chaff & roasting crud. That fan and rubber molding essentially replace the germanium window ($$!) that covers the V1 IR sensor.

IBTS has a view of the beans but the beans are never in direct contact with the germanium view window as can happen with the V1 IR installation. As I understand it that germanium window is somewhat fragile so you have to use care in cleaning it. There used to be info on the V1 Drum Temp IR sensor window maintenance on the Aillio site. You might want to do some searching there but if you strike out you might try contacting Aillio Support… I bet they still have the files available.

A lot of great tasting coffee has been roasted on V1 Bullets. Other than a different temperature range & shape for Drum Temp & DT-RoR (labeled I-RoR) curves compared to V1.5/V2 machines, the profile posted here looks great! The labeling upper left (“IBTS Temp”) is unfortunate for your purposes but you know the difference.



Thanks Bruce! That was most helpful. Yes it’s indeed an IR sensor… not the IBTS. Renamed the topic title for clarification. Good to know the profile looks good! Hoping to upgrade my v1 for sure.