Just received two more Seiko twin quartz watches. A Grand Quartz calibre 9943 and a King Quartz calibre 9723. Both are going into the constant temperature chamber for an accuracy check.
First the Grand Quartz.
Then the King.
I have two other Seiko twin quartz watches and one Longines VHP with a twin quartz movements. These have been calibrated and keep time well within their stated accuracies.
We will see if these two new Seikos live up to the HeQ standards.