You might have wanted to talk to Bill Lull about circular
charts before youn committed.

According to MOH Library:
>
> At 08:25 AM 2/14/96 EST, you wrote:
> >I am trying to purchase a recording hygrothermograph for monitoring
> >in a newly restored 1904  building.  Does anyone have any strong
> >recommendations for brands and/or suppliers.  Is Belfort in Baltimore
> >still in favor?  Any tips or things to watch out for?
> >
> >
> At the new Museum of History in Raleigh, we use Hygrothermographs by Omega
> Engineering.They are a very slim unit with circular charts that are easier
> to change than the old drum type.The unit measures 13.5" high x 10.5" wide
> x2.5" deep.
> Colour is beige and they blend into exhibit decor very nicely.These have
> digital motors instead of analogue and draw less volts for economy of
> operation.They operate best on two Duracell batteries for several months and
> are shipped with a/c adapters.
> There are two lights to the right of the dial face,(operate only on DC)very
> handy when changing charts in a dimly lighted gallery full of visitors.To
> the lower right hand corner is a digital display to check gallery climate at
> any instance.
> An audible alarm is incorporated in the design,it's use optional should the
> batteries weaken.
> The charts are round and two sided and so there is a cost saving in flipping
> charts and it reduces filing space required.They are packed with a small
> quantity of charts in C and F degrees,daily,weekly and monthly.I found
> weekly to suit my purpose and so I suggest if you order a unit to ask on the
> order for all charts packed to be what you require.The others will just
> gather shelf dust.
> The customer service by Omega is excellent.Cost is appx $535.00ea.I have 17
> units in operation.
>
> Omega Engineering
> One Omega Drive,Box4047
> Stamford,CT 06907-0047
> Telephone (203)359-1660  (800-826-6342 Sales and Service)
> FAX (203)359-7700
>
> I have also had experience with the old German made, key wind-up drum
> units.These are workhorses and sometimes may be found for resale at
> instrument repair shops or talk to a horologist.They seem to last forever
> and aren't subject to power failure.
> Be sure to have it recalibrated if it hasn't a tag indicating so.
> Cole- Palmer sells a miniature drum type that operates for months on one AA
> size battery.
> If you have visitors in the gallery you may ask your mount makers to
> fabricate lexan shelves to keep them out of reach of curious children.
> Our security staff found a child lying on the floor in a galley speaking
> into the relative humidity sensor thinking it was a tape recorder.The father
> was quite irate when the guard asked that he replace it on the shelf.Such
> are the joys of museum life!
> Regards
> Len Hambleton-Chief Conservator
> The North Carolina Museum of History
> Raleigh,NC  [log in to unmask]
>