Read it in three steps
Rate at the arrow, dose on the rim, days on the dial
Set your dose rate
Turn the dial until your rate on the blue scale sits at the blue arrow. TM 1019 Condition D is 10 mrad(Si)/s.
Find your total dose
On the fixed outer ring, find your target dose in krad(Si).
Read the days
The white number on the dial beside that dose is the irradiation time in days. Interpolate between marks.
ExampleSet 10 at the arrow. Beside 50 krad(Si) the dial reads just under 60: the exact figure is 57.9 days.
On screen
Try the wheel
Move the sliders. The dial turns exactly as the printed one does.
Irradiation time
57.9 days
8.3 weeks
Irradiation time only. For margin, anneal and completion dates use the full calculator.
Plan an exposure with usWhat it leaves out
A planning tool, not a schedule
The wheel shows irradiation time. A real campaign also needs setup and dosimetry checks, interim readouts, any anneal your procedure calls for, and shipping. Low-dose-rate exposures hold a source position for that whole time, which is why reserving the window early matters.