# Tag Info

31

It's a Campbell-Stokes sunshine recorder, used to record the times at which the sun is shining. It acts as a lens, focusing the sunlight onto a piece of card. If the sun is shining, the focused beam will burn a hole through the card at that point. Here's a closer view of a sunshine recorder in Wendelstein, Bavaria: Source: Wikimedia Commons And here's a ...

17

Mark's answer about mercury barometers is correct - but it is not the complete story. Barometers were initially constructed using water, not mercury, on the manometer principle. Water is lighter than mercury, so a water barometer requires a 10.3m tube. 1mbar is therefore roughly 1cm, and 0.1mbar measurement is clearly trivial using a ruler with 1mm ...

9

Those are Sun/Moon multispectral photometers and ski radiometers. These are instruments that can scan the sky or track the Sun/Moon for direct measurements. They measure light intensity at multiple narrow wavelength bands, and are designed to measure atmospheric aerosols content and characteristics. The ones in the third image seem to be a CIMEL CE-138 Sun ...

9

A mercury barometer is a simple, easy-to-build barometer that turns the problem of calibrating a pressure standard into one of calibrating a length standard. Accuracy of length standards has long been a concern of merchants and those regulating them; in 1692, the standard would probably have been a brass prototype yard in the possession of the Royal Society....

8

Yes, you can measure seismic energy with accelerometers. Most people do. There are three ways to measure seismic energy: by displacement $x$, velocity $\dot{x}$, or acceleration $\ddot{x}$. Loose-spring devices like geophones measure velocity; stiff-spring devices like MEMS and relative gravimeters measure acceleration: they are accelerometers. Those used ...

8

I've built DIY conductivity probes for subglacial measurements. Unfortunately my sensors remain under ~100m of ice so I haven't be able to recover them to check the calibration, but for the same reason, I've taken multiple measurements to reduce calibration drift, as I'm unable to re-calibrate them. So far, they have produced sensible data for 2+ years, but ...

7

The magnitude of an earthquake is related to the total energy released, therefore to estimate it from a seismogram you need to know the distance to the source. In the case of the Richter scale for example, the relationship between magnitude and seismogram amplitude is defined for a standard distance. If you have only one seismograph, you can not triangulate ...

7

Nereus as is, is currently not replaceable, but it was insured at a replacement value of $3.1 million, and my understanding Woods Hole currently plans to replace it, though unlikely at this point that there's a solid timeline for this taking place. Landers, fish traps, and sediment core samplers will still be actively used, but again, these are not really ... 6 I think the greatest impact may be upon the careers of the investigators on the project. Decades of work can be invested in the planning and building of a submersible or space probe, it an inherently risky undertaking, if it gets destroyed in the process, who takes up the job of learning from the experience and trying again? Hopefully, institutions support ... 6 On the synoptic scale (thinking along the lines of cyclones, weather fronts etc.), then that's a pretty significant drop in that amount of time. A bomb or explosive cycogenesis in meteorological terms is defined as a drop of at least 24mb in 24 hours, so your observation easily fits this description of being a significant rapid pressure change. There's a ... 6 I don't think they are using that level of accuracy for the old readings. Reporting pressure, in hPa, to one decimal place is being done for recent measurements. There are no values given for very old readings. As for the record reading of 1053.6 hPa for 1902, I suspect that is a mathematical conversion of a reading that was most likely recorded in inches ... 6 I am going to take a guess here because I have not used these instruments in real life but given the content of this Mauna Loa Observatory I Exploratorium video - fast forward the video to 3:43 and see the yankee name on that instrument. Then I did a google search on that and got this link - Yankee list of products So A is a Pyranometer and B is a ... 5 I think answering your questions in reverse will make more sense. The "size" of PM is typically the aerodynamic/inertial impaction size, as you guessed. My standard reference for this is this paper. Their figure 8 is a rough schematic of where particles of different size deposit in the lungs. Things with very large or very small inertial impaction size get ... 5 Carbon monoxide (CO), natural gas & hydrocarbons, VOCs, ammonia, etc. In this Chemistry SE answer and this Electronics SE question I discuss how the family of MOS gas sensors work. They can measure a large variety of different gasses that can react with atomic oxygen (O rather than$\small\mathsf{O_2}$). I'll quote from this question: ...... 5 The upside down funnel-shaped attachment is used to prevent rain-water getting inside the inlet of instruments which analyse ambient air. Usually, these instruments are air pollution monitoring instruments like ozone analyser, carbon monoxide analyser, particle concentration analyser, etc. One may think why can't just use U-shaped tube (inlet). In case of U-... 4 Accelerometers, preferably triaxial (i.e., those that record horizontal and vertical motion). Beyond that your question is indeed a bit too open-ended. Some use many cheap MEMS (http://onlinelibrary.wiley.com/doi/10.1029/2008GL036572/epdf; https://www.theverge.com/circuitbreaker/2017/7/13/15963996/raspberry-pi-seismograph-early-warning-earthquakes; these are ... 4 In the latest EOS number there is an interview with Woods Hole Oceanographic Institution's scientist Timothy Shank in which he responds to the question. It seems that we are back to just snapshots and grad samples of the hadal ecosystem. Eos: What research opportunities have been lost as a result of the loss of Nereus? Shank: The ability of Nereus to do ... 4 I am going to just give a slightly different perspective to the answer above by actually naming the instrument in OP's question. Based on the name BSRN in OP's second image that actually translates to this institution - Baseline Surface Radiation Network the cylindrical instrument in the photograph shown is actually a pyrheliometer. In an earlier answer I ... 4 I'm going to go old school with this one. The following pictures are the relevant pages from: Environmental Engineering in South African Mines, The Mine Ventilation Society of South Africa, 1989, pp 451-455. They give the psychometric equations that are required to calculate relative humidity from wet & dry bulb temperatures. For simplicity, I use the ... 3 The transmissometer setup should be quite easy to build in principle, but it could be hard to get accurate values. I did a very similar instrument but to measure water transsmisivity (a.k.a. turbidity). If you are new to Arduino you can start with the Arduino UNO board, and this is a good guide on how to get started. I got started myself with the video ... 3 The table below gives you a nice summary snapshot up to 2015. Reference: Kamp, P.J., 2016. Towards an Ultra Sensitive Seismic Accelerometer (Master's thesis, University of Twente). Sercel accelerometer, the top one in the table, is widely used in Oil and Gas industry, for example, to monitor induced seismicity. Below is an excerpt from the article: "A ... 3 Following @ Friddy's comment, I started reading Aethlabs AE51 FAQ and was quite surprised! While a conventional aethalometer use a long tape and move it to the new position after each measurement (which could be as fast as one measurement per minute), the compact device shown in the image in question uses a single filter position, and just keeps measuring as ... 3 How are barometric pressure measurements traceable over centuries to 100 parts per million accuracy? To compare records of barometric temperature, this standard doesn't necessarily have to be met. Recording barometric pressure to 100 parts per million precision has been possible for centuries because it's reasonably trivial to observe movement of the level ... 3 It appears the issue with using accelerometers for characterizing earthquake intensity is their lack of sensitivity, as you can read from the live science website. But that does not mean that accelerometers can't provide useful information about earthquakes, particularly larger quakes. Stanford University has established the Quake-Catcher Network to ... 3 I think the core of the answer should lie in what was already stated in the comments. These detectors are not scientific instruments. For air quality monitoring much more sophisticated analyzers are needed to measure the concentration of the gases. The example in the link works on a basis of gas filter (filled with CO) and it can just as well be used for$\...

2

In the Arduino compatible sensors I've found, CO, methane, and other common raw sensors are as little as US\$1 from China. The cheapest$\small\mathsf{CO_2}$sensor (also from China) I found was around US\$35. Otherwise, raw sensors components are around US\\$100. The only real difference between the raw sensors and scientific instruments are that the ...

2

First you need to make the difference between a detector and a sensor, while the first one only shows that some gas is present, the second has to show the amount of gas. Usually a sensor needs calibration, where you must give two points with different concentrations, this is not easy and you need a known source of concentration. Also this means that a ...

2

As noted in the comments, this is actually a much more complex question than it might seem at first. Answering fully would require a very involved and technical discussion of single-beam surveying's inherent errors and their causes (water velocity, side slope reflection, highly transmissive hydrocarbon-rich anthropocene silt, and other such complications). I ...

1

The maximum reading was taken at Aberdeen Observatory and they still have a barometer which was in use during the period the reading was taken (the inscriptions dates it to 1888 and after 1922 it was still in use). It's not a mercury one - mercury is relevant as the article states records go back to 1692, before aneroid barometers were invented, though does ...

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