• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

Laserwriter II Ozone Filter

jmacz

68020
For those with functioning Laserwriter IIs, have you replaced the ozone filter and if so, with what?

The Laserwriter IIf I recently picked up had a completely crumbled ozone filter. There isn't much on the site about it outside of Printerworks which is no longer in business.

I know it's not the same thing but can I just drop a filter bag with activated carbon in there as a replacement?
 
For those with functioning Laserwriter IIs, have you replaced the ozone filter and if so, with what?

The Laserwriter IIf I recently picked up had a completely crumbled ozone filter. There isn't much on the site about it outside of Printerworks which is no longer in business.

I know it's not the same thing but can I just drop a filter bag with activated carbon in there as a replacement?
TBH, I had no idea that anyone was concerned about ozone and particulate emissions until much more recently. I did a search for "printer ozone filter" and came up with a bunch of hits for what looks like the same sort of carbonized foamy material one might buy for home air filters.
 
I haven't bothered to replace the filter in my LaserWriter II. I don't have it on for long periods of time.

However if you want to, I think that the HP part number you're looking for is the RF1-2130-CLN. The LaserWriter II uses a Canon SX engine, the same as the LaserJet II, so parts for that will work in it. There seem to be some NOS parts available on various sites - whether they are any good is another question, however.
 
From the HP LaserJet II / III Service Manual (same Canon engine as the Laserwriter II series):

"Ozone Emissions:
General - The corona assemblies found in laser printers and photocopiers generate ozone gas (O3) as a by-product of the electrophotographic process. Ozone is only generated while the printer is actually printing (i.e. while the corona assembly is energized). Underwriters (UL) has established a standard for ozone emissions. All LaserJet printers meet this standard when shipped from the factory.

Employer Responsibility - Because ozone can be an irritant, various regulatory agencies have stablished limits to the amount of ozone to which employees may be exposed. The employer should provide a work environment that meets the following standards:
* A person may not be exposed to an average concentration of greater than 0.1 part per million (PPM) of ozone for a period of 8 hours.
* At this time, the American Conference of Governmental Industries Hygienists (ACGIH) has proposed a ceiling limit of 0.1 PPM for ozone

Recommended for Minimizing Ozone Exposure:
Almost all ozone concerns arise from abnormal site or operating conditions. The following conditions may generate an ozone complaint:
* Multiple laser printers in a confined area
* Extremely low relative humidity
* Poor room ventilation
* Printer exhaust port directed toward the faces of personnel.
* Existing ozone filter in need of replacement (see chapter 4)
* Long, continuous printing combined with any of the above conditions

Chapter 4:
Ozone Filter replacement
"... The filter should be replaced every 50,000 pages...Visual inspection will not show that a filter is dirty, page count is the only reliable indicator on which to base a decision to changea filter."

Hmm, this explains why they changed to a charge roller in later models to avoid this ozone "smell". Some people, including myself, complained of feeling lightheaded and now that makes sense. As I recall, it was just a carbon-based filer. We did blow air through them when they were dusty and replaced them if they were crumbling or when a maintenance kit was replaced.

Thanks for the memory lane!
 
Back
Top