Coherent Innova 90 Ion laser

[weeba2kv]

Ok i have a Coherent Innova 90 Ion laser

I just want to ask some information according GAS and re-filling
The laser I am sure will not run since its a gas tube laser. The gas ends up being absorbed into the metals in the tube since it did a last run 3 or 4 years ago , this causes a low gas pressure situation and will not allow it to start.

Some pictures

[buffo]

Send a Private Message to rgb-gas here on the forums. His real name is Jeff, and he has a source for replacement plasma tubes for the I-90. If I remember correctly, they can be purchased for around $800. These are NEW tubes, not refurbished ones. All you need to do is remove the old tube from the head and install the new one and you are ready to go. (I've done it myself; it takes about 15 minutes if you are very nervous like I was. A pro can do it in 5 min. The hardest part is getting the tube out of the magnet.)

Re-gassing that tube is going to cost a good bit more than $800, unless you know someone who already has the equipment and is willing to do you a huge favor.

Adam

[weeba2kv]

So This system doesn't have a autofill system ?

[buffo]

So This system doesn't have a autofill system ?

The I-90 medical units have a pair of valves and a gas reservoir that can be used to partially refill the tube (and can even be used to re-pump the tube if you have the right tools and experience), but I don't recall seeing that arrangement on the scientific version of the I-90 that I mesed with a few years ago. (I still have my I-90 medical unit, but I didn't buy the scientific unit that I also looked at back then, so I could be mistaken.)

Remove the metal cover on the head and take a look. If you have a gas fill system, it will be obvious. Look for two cylindrical valves installed in line on a flexible tube that connects the plasma tube with a small reservoir. You will see a pair of wires coming out of each cylindrical valve.

Note that even if you have a fill system, the tube could still be out of gas.

Adam

[weeba2kv]

Btw why does it say 50 Hz ? in USA they run @ 3300 RPM to get 60 Hz right ? we run @ 3000 RPM - 50 Hz but why the laser comes from Cali. and is made for 50 Hz ?

[buffo]

Btw why does it say 50 Hz ? in USA they run @ 3300 RPM to get 60 Hz right ?

Actually, a standard 2-pole generator turns at 3600 RPM in order to generate 60Hz.

but why the laser comes from Cali. and is made for 50 Hz ?

The original assembly plant was in California, but they have to build lasers for people all over the world. Obviously this laser was designed to be sold to a European user, which is why it's set up for 50Hz power instead of 60Hz.

Adam

[mixedgas]

Please do not confuse the FAQ "low pressure" for air cooled tubes for medium frame water cooled tubes. They are a slightly different beast and different rules apply.

That is a I90, not a I90MRA, so used/low cost medical tubes are out. Besides, they do not fit, they are about 2 inches longer then the tube in that unit and the gas resivoir is in the wrong place. However tubes and heads for I90 are all over the place. They are not expensive.

The head has a pressure control system. It will fill when enabled. Even with a low pressure light lit, it will start. It cannot determine if it is low pressure unless it starts. If its more then about 10 volts low, it will time out and extinguish. However you can still initiate a fill with the fill switch in the head. When your sure you have a pressure problem, and it needs to run for 20 minutes before you know for sure, then PM me and I can walk you through it. You do not want to toggle the fill switch without instruction, there is a technique to it, and you can easily overfill, because it can take up to 20 minutes for the gas to diffuse into the active bore.

What most often happens is no one reads the manual and it needs either a full alignment including walking, or a fill initiate. So it gets tossed into a dumpster before end of life.

I max is 35 amps for that tube, although a few varients allow 40. When starting it, turn the light mode knob on the controls fully counterclockwise and the current knob to about 2 turns clockwise. Until the optics are properly aligned, light mode can ramp the tube to full current.

Pressure lights come on over a wide range of operating conditions, they are a guide, not a absolute. The absolute is still a voltmeter and setting it to Iref, which is as close to 35A as the tube will let you get.

Next up, because it has a fill system, it is more likely to be high pressure then low. The teflon o-rings in the fill chamber weep a bit of gas over time.

There is a diagnostic manual that is rather complete for those. They pretty much have four possible states when they are purchased used:, A. incinerated power supply, B. One of the 4 passbank transistors is blown, C. Cracked open flow switch housing, D.They work just fine. Most of the time it is the last case, for that laser is about as tough and well built as possible. It has protective circuits that are second to none. B,C, and D are easily cured.

You'll have to try it with the head covers on, I do not see cover interlock defeat plugs in the picture. There might be a small black plastic case with spare parts and the tuning tools, optional optics, spare optics holders, and the defeat plugs.

When learning about that laser and first operating it, DO NOT flip the UV/VIS switch with the power supply on. All it does is increase the magnetic field, you have to change optics sets to get UV. But it will surge a fuse that is hard to get to.

The laser will run on 60Hz, but you have the export version which is tuned for 50 Hz. A small timing capacitor is changed on six timing circuits on the regulator board and the cathode transformer iron is less efficient on 50 hz, so it will have a tap on the internal transformer changed for 50 Hz. For 50 Hz, the timing pedistal waveform is not that different, and the laser will run on 60 Hz.

If you email Coherent with a serial number for the head and PSU, and you correctly answer a few questions that they may ask, odds are they will send you a confidential PDF of the manual. You may have to promise them to never post it on the internet. This is how they keep track of laser lifetime and where each laser is, and they take it seriously.

Steve



Steve

[weeba2kv]

Thank you so much mixedgas.