CO₂ pressure regulator

01 · THE GAUGE DOES NOT MEASURE CONTENT

Weigh the cylinder, do not read the needle

Inside the cylinder the CO₂ is liquefied, and while any liquid remains the vapour pressure stays practically constant. The needle reads almost the same on a full cylinder as on a quarter-full one, and only drops when it is nearly empty.

The way to know what is left is to weigh the cylinder and subtract the tare, which is stamped on the shoulder. The gauge tells you there is pressure and lets you watch the outlet; it is not for planning refills.

02 · HOW MUCH GAS, AND HOW LONG

A gentle flow, and no more than needed

CO₂ immobilises the queen rather than fully anaesthetising her, and the effect reverses within minutes. What you want is a gentle, steady flow over the holding tube — the least that keeps her still while you work.

Established practice in instrumental insemination includes a second exposure the following day, which brings forward the start of laying. Do not overdo it: CO₂ is a tool, and repeated or prolonged exposure costs the queen in longevity. Follow the protocol of your insemination kit.

03 · YOUR CYLINDER'S THREAD

AG 3/4 inch, but check it

The connection is AG 3/4 inch, on the right-hand side, standard on Schley equipment. That said: CO₂ cylinder threads vary from country to country, and what is standard in Germany need not be standard at your local gas supplier.

Before ordering, look at the thread on the cylinder you will use, or ask your gas supplier. An adapter can be found, but it is better to know beforehand than on the day of the session.

04 · BEFORE YOU BUY

This is the regulator, not the kit. The CO₂ cylinder is separate and gets refilled at a gas supplier.