Need source for temperature and humidity gage

[chasf]

I would like to monitor the temp and humidity of our inspection room in order to keep it at 68º +/-2º.
The gages I have seen so far are accurate within 2º.
Can anyone direct me to a source for a more accurate gage?
One supplied with a NIST cert would be even better.

 

[SteelMaiden]

Have you checked any laboratory supply catalogues? I am sorry, it's been so long ago that I worked in a lab I can't remember the names of the suppliers we used, but it seems like we bought several different kinds of thermometers all from a lab supply company, and they all came with a NIST traceability certificate.

 

[KeithM]

Compact Temperature and Temperature/Humidity Data Loggers, Dickson*

There are several ways to go about this.
If you want to record several readings throughout the room and print reports to keep on file you can use Dickson Data Loggers. Here's a copy of their specs from the VWR website.
Catalog Number: 13450-768
Supplier: Dickson
Description: Compact Temperature/Humidity Data Loggers. Range: -20 to 70[degree]C; 0 to 95% RH (non-condensing). Accuracy: +/-1[degree]C (temperature); +/-2% (humidity). Dicksonware* data software. Records data in configurable 10-second to 24-hour intervals (10-second increment). 3.4x2.7x1.2cm. Pack of 12.


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Also you can buy a wall mount unit farely cheap so you can see real time what the readings are and fill out a log sheet on a daily or hourly basis with one or sevral of these.




VWR® Traceable™ Big-Digit Thermometer
Supplier: VWR International
Find Similar Items in Product CategoryThermometers, Electronic and Digital
Supplier: VWR International



Window or Wall Mount
Automatic Minimum/Maximum Reset

Use outdoors and in storerooms, fume hoods, labs, cleanrooms, refrigerators, and plant areas. Thermometer may be attached to the outside of a window to view outdoor temperatures. Features a transparent display with 3.2cm (11/4") high digits to show current and minimum/maximum temperatures, which are automatically cleared and updated daily.

A serial-numbered certificate is provided from an ISO 17025 calibration laboratory accredited by A2LA to indicate traceability to standards provided by the National Institute of Standards and Technology.


Resolution: 0.1°
Accuracy: ±1°C
Dimensions: 8.9W x 10.8H x 1.9D cm (31/2 x 41/4 x 3/4")
Weight: 227 g (8 oz.)



Ordering Information: Supplied with mounting tape, pre-cut Velcro® squares, and AAA battery.



Range VWR Catalog# Unit Price Quantity
–13 to 158°F 36934-156 Each $23.72
–25 to 70°C 36934-158 Each $23.72

There are about 10 pages of results on the VWR website as well as the Dickson data logger website. Some like chart recorders and use them as well as they will do Temp and RH as well.
GE Sensing also make some real nice data loggers with higher accuracy but they are very expensive. It all depends on what spec you would like to meet.
I hope this helps.

 

[Jerry Eldred]

Hart Scientific makes one specifically for calibration labs. Their web address is www.hartscientific.com. The advantage of such an instrument is that it is designed to log and record temperature history, and can be set up with alarms for if your lab goes out of limits.

There are a lot of options if you just want to simply read the temperature. But not very many options if you want to log/record temperature and humidity and include all the functionality needed by a calibration lab.

I recently upgraded my temp/humidity recorders from very old Honeywell T/H recorders to a new data logging T/H meter (I ended up with Extech, a lower priced option due to budgetary constraints - but strongly preferred the Fluke/Hart unit).

While we're on the topic, I'd be interested in anyone's opinions on this as to what brands are out there that provide Temp/RH with logging and alarms. Here are the ones I know of:

- Hart Scientific DewK series (best one on the market, I think).
- Extech RH520A T/H datalogger (budget priced, and not nearly as many features as the Hart).
- Omega (Newport/Whitebox/etc.) CT485 T/H chart recorder with detachable/extendable probe (old technology, lower accuracy, lower priced, not very many features).

What else is out there for cal labs?


DISCLAIMER: I don't work for any of the above, or in any way profit. This is just my professional opinion.

 

[Hershal]

Keith and Jerry are correct,

The dataloggers are much better. They do not require changing of charts, they can dump to a computer for long term tracking, and accredited calibration is available for them.

One thing to consider is to obtain two dataloggers and stagger their calibration cycle.

 

[tsmith7858]

I agree with everyone else, data loggers work good. I have used Onset Hobo data loggers in the past. They are <$100 USD each. I think the accuracy is about +/- .5 C.

Hershal makes a great point on more than one. We had multiple on site that were in use and kept 2-3 as back up, for swap out during calibration or for testing purposes.

 

[Jmcdonald870]

Omega has some nice data loggers also. I just bought one and it works great!

Here is the link to the one I bought. http://www.omega.com/pptst/CTXL.html


Joe

 

[BradM]

Omega has some nice data loggers also. I just bought one and it works great!

Here is the link to the one I bought. http://www.omega.com/pptst/CTXL.html


Joe

Agreed. We have had several of those for a long time. They are reasonably priced, easy to use, easy to get parts, and fairly easy to calibrate.

One thing about these... Watch that the pen tracks with the display. I have noticed sometime that the pen has to be adjusted (display says 30%RH; pen is tracking 32%RH or more).

 

[chasf]

Thanks for all of the input. I decided to go with the unit found here.


http://www.fishersci.com/wps/portal...rossRefData=null&highlightProductsItemsFlag=Y