I posted about the new G-Pendant from the HoboDepot last week. I showed an experiment some of my students were conducting relating to the benefits of shoes for absorbing shock rather than transferring it to your knees and back.
The maximum g-force on the graph was above 5 g's (The maximum possible reading is 3 g's in any one direction). We were graphing the sum of the three axies rather than just the x direction (straight down). Birch, a retired physics teacher pointed out we may have been maxing out the pendant in one of the component directions. Well, he was right. We went back and analyzed the data today and found with no shoes we did max out the g-force in the x-direction. With shoes we only maxed out for a few of the steps.
We played some more and found it is hard to keep under 3 g's. With this limitation it is still possible to do some good labs.
We put the sensor on the inside edge of a roll of masking tape and rolled it. You have to roll it really slow to avoid maxing out centripetal force. However, it is easy to see when each rotation happens. So, we rolled it down a ramp and were able to calculate acceleration. With a roughly 20 degree angle we were able to estimate acceleration to an acceptable 10% error. Any steeper and we would have maxed out too fast to collect any usable data (we'll confirm this later).
Tomorrow I'm going to have them do periodic motion, both pendulum and bouncing on a spring.
In case you're wondering. I have a few highly motivated students who have eighth hour off and like to hang out in the physics room (who doesn't really?), so I've put them to work.
Technorati Tags: education, probeware, falconphysics
Showing posts with label hobo. Show all posts
Showing posts with label hobo. Show all posts
Monday, October 02, 2006
Thursday, September 28, 2006
Way Cool Probeware
I just managed to acquire more HOBO data loggers. Now I need to play with them so I can demo them at the meetings I'll be presenting at in October (DMAPT Oct. 3, MDSTA Oct. 21, and hopefully MiAAPT Oct. 14). I've played with some of their other products before and have been impressed with their ease of use, portability, and affordability. Now I'm even more impressed.
About a year ago Onset Computers and the HOBO Depot released their first pendant logger, which measures light and temperature. The pendant loggers are fully sealed and waterproof. They communicate with the computer through an optical coupler plugged into a USB port. There is a magnetic switch inside the pendant to tell it when it is in the coupler. The switch can be used, with a magnet, to trigger the logger to begin taking data.
The basic HOBO interface is easy to use and quick to master. You plug the HOBO into the computer and then use the HOBO software to configure the logger. You "launch" the logger and put it somewhere you want to record data. The logger will collect and store data until its memory is full or you connect it to the computer again. The data are stored and plotted. The data can also be exported into Excel or another spreadsheet to be analyzed.
Until recently the main focus of the HOBO loggers has been environmental (light, temp, humidity). The newest logger is aimed squarely at physics. The new pendant measures acceleration/gravity. It contains a three axis accelerometer and is capable of collecting data much more quickly than the older loggers. The g-pendant can take up to 100 samples per second. The older loggers won't log data faster than once a second.
G-Pendant Stats:
Technorati Tags: education, probeware, falconphysics
About a year ago Onset Computers and the HOBO Depot released their first pendant logger, which measures light and temperature. The pendant loggers are fully sealed and waterproof. They communicate with the computer through an optical coupler plugged into a USB port. There is a magnetic switch inside the pendant to tell it when it is in the coupler. The switch can be used, with a magnet, to trigger the logger to begin taking data.
The basic HOBO interface is easy to use and quick to master. You plug the HOBO into the computer and then use the HOBO software to configure the logger. You "launch" the logger and put it somewhere you want to record data. The logger will collect and store data until its memory is full or you connect it to the computer again. The data are stored and plotted. The data can also be exported into Excel or another spreadsheet to be analyzed.
Until recently the main focus of the HOBO loggers has been environmental (light, temp, humidity). The newest logger is aimed squarely at physics. The new pendant measures acceleration/gravity. It contains a three axis accelerometer and is capable of collecting data much more quickly than the older loggers. The g-pendant can take up to 100 samples per second. The older loggers won't log data faster than once a second.
G-Pendant Stats:
- Max 3 g in any one direction (very easy to max out)
- Should survive a drop from 3.5 m
- Accuracy: 0.753 m/s^2
- Operating range -20 Deg. C to 50 Deg. C
- Submersible up to 30 m
- Weight 18 g
- Cost - Complete Kit: $99 (until January), Individual Pendant: $69 (volume discount available)
Technorati Tags: education, probeware, falconphysics
Friday, August 18, 2006
Cheap Probeware
iScience Project is clearing out their stock of Serial Hobos for really low prices, but you have to act before August 25th, 2006.
Officially it's an Auction with a minumum bid of $18 for a kit or $35 for buy it now (normally $139/kit).
That buys you a small device (half the size of a deck of cards) that will record temperature, light, and humidity. It also comes with an external temperature probe on a 6' lead (so you can take two temps at the same time).
Hobo's are pretty cool. You plug them into the computer and use their software to set them up (what type of data to record and how often a reading is taken). Then you unplug it and leave it where you're collecting data. Once done you plug it back in and download the data to the computer.
These are cheap enough you could send them home with your kids for at home experimentation. There are hundreds of activities on the iScience Project page to use with Hobos if you can't think of any yourself.
They also have a loaner program so you can borrow Hobo's before you buy and there is usually some sort of contest you can enter to win a Hobo as well.
I've played with some Hobo's and will be more than happy to share my thoughts with you. AFAIK the serial ones are Windows only. They do sell USB ones that will work with Mac OS 10.2 or later (but they'er not super cheap right now)
Here's the info for the auction:
The Auction will begin now and end at 12 noon EST on Friday August 25, 2006. You will be notified by email within 24 hours 1) when you are the high bidder and 2) when you have been outbid. On Friday August 25 from 8AM until Noon (EST) you will be notified instantly. There will be a minimum bid of $18 per kit and $10 per individual HOBO to cover the cost of a new battery, shipping and the full 1 year warranty that will come with your HOBO. You can also use the “Buy it Now” option to own it immediately. All transactions must be on a Visa, Mastercard, AMEX or a school PO.
FAQ - What is demo stock at The HOBO Depot and Onset Computer Corporation? Any product that ever has been returned used or unused and any product that ever had a blemish or misprint on the casing. All of our demo stock has fully functioning components that we warrant for a full year. If any product is not working we guarantee we will replace it ASAP. All of these products come with a PC serial port connection and serial port cable (9 pin trapezoid). You would either need an available serial port (older computers have them) or a new serial to USB Keyspan adapter ($39 at any store that sells computers). All of these kits come with free PC Boxcar 4.3 software which is compatible with Win98 to WinXP and one free serial (9 pin) cable and one new battery.
So here you go - just put in your bid (minimum $18 for kits & $10 for the individual HOBO units).
#1) "Brand New" boxed serial HOBO Henry Kits - Minimum Bid =$18, My Bid =_$, or Buy it Now = $35 Each (Sells for $139) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext), (1) 6 Ft External Temp Cable, (1) PC Serial Cable, (1) HOBO Henry & Activity Book, 300 Labs on CD, (1) BoxCar PC Software
#2) Demo Serial Intro Kits - Minimum Bid =$18, My Bid =_$, or Buy it Now = $30 Each (Sells for $139) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext), (1) 6 Ft External Temp Cable, (1) PC Serial Cable, (1) BoxCar PC Software
#3) Demo HOBOs only - Minimum Bid =$10, My Bid =_$, or Buy it Now = $18 Each (Sells for $95) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext) or any HOBO on this web page and that is all. We assume you want the H08-004-02 unless you indicate differently. Great place to stock up on class sets.
#4) Demo External 6 Foot Temperature sensor TMC6- HA (same specs as TMC6-HD that replaced the HA) - Minimum Bid =$10, My Bid =_$, or Buy it Now = $18 Each (Sells for $30) Includes (1) TMC6-HA Sensor and that is all.
#5) Demo HOBO H9 Shuttle Data Transporters H09- 003-08 - Minimum Bid =$18, My Bid =_$, or Buy it Now = $30 Each (Sells for $159) Includes (1) H09- 003-08 HOBO H9 Shuttle Data Transporter - Perfect for collecting the data out in the field for up to 50 of your Demo HOBOs on one Shuttle (Palm like HOBO data storage).
Auction Contact Information
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
email: rich@hobodepot.com
phone: 877-564-4377
web: http://www.hobodepot.com
Technorati Tags: education, probeware, falconphysics
Officially it's an Auction with a minumum bid of $18 for a kit or $35 for buy it now (normally $139/kit).
That buys you a small device (half the size of a deck of cards) that will record temperature, light, and humidity. It also comes with an external temperature probe on a 6' lead (so you can take two temps at the same time).
Hobo's are pretty cool. You plug them into the computer and use their software to set them up (what type of data to record and how often a reading is taken). Then you unplug it and leave it where you're collecting data. Once done you plug it back in and download the data to the computer.
These are cheap enough you could send them home with your kids for at home experimentation. There are hundreds of activities on the iScience Project page to use with Hobos if you can't think of any yourself.
They also have a loaner program so you can borrow Hobo's before you buy and there is usually some sort of contest you can enter to win a Hobo as well.
I've played with some Hobo's and will be more than happy to share my thoughts with you. AFAIK the serial ones are Windows only. They do sell USB ones that will work with Mac OS 10.2 or later (but they'er not super cheap right now)
Here's the info for the auction:
The Auction will begin now and end at 12 noon EST on Friday August 25, 2006. You will be notified by email within 24 hours 1) when you are the high bidder and 2) when you have been outbid. On Friday August 25 from 8AM until Noon (EST) you will be notified instantly. There will be a minimum bid of $18 per kit and $10 per individual HOBO to cover the cost of a new battery, shipping and the full 1 year warranty that will come with your HOBO. You can also use the “Buy it Now” option to own it immediately. All transactions must be on a Visa, Mastercard, AMEX or a school PO.
FAQ - What is demo stock at The HOBO Depot and Onset Computer Corporation? Any product that ever has been returned used or unused and any product that ever had a blemish or misprint on the casing. All of our demo stock has fully functioning components that we warrant for a full year. If any product is not working we guarantee we will replace it ASAP. All of these products come with a PC serial port connection and serial port cable (9 pin trapezoid). You would either need an available serial port (older computers have them) or a new serial to USB Keyspan adapter ($39 at any store that sells computers). All of these kits come with free PC Boxcar 4.3 software which is compatible with Win98 to WinXP and one free serial (9 pin) cable and one new battery.
So here you go - just put in your bid (minimum $18 for kits & $10 for the individual HOBO units).
#1) "Brand New" boxed serial HOBO Henry Kits - Minimum Bid =$18, My Bid =_$, or Buy it Now = $35 Each (Sells for $139) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext), (1) 6 Ft External Temp Cable, (1) PC Serial Cable, (1) HOBO Henry & Activity Book, 300 Labs on CD, (1) BoxCar PC Software
#2) Demo Serial Intro Kits - Minimum Bid =$18, My Bid =_$, or Buy it Now = $30 Each (Sells for $139) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext), (1) 6 Ft External Temp Cable, (1) PC Serial Cable, (1) BoxCar PC Software
#3) Demo HOBOs only - Minimum Bid =$10, My Bid =_$, or Buy it Now = $18 Each (Sells for $95) Includes (1) H08-004-02 HOBO data logger (Temp/RH/Light/Ext) or any HOBO on this web page and that is all. We assume you want the H08-004-02 unless you indicate differently. Great place to stock up on class sets.
#4) Demo External 6 Foot Temperature sensor TMC6- HA (same specs as TMC6-HD that replaced the HA) - Minimum Bid =$10, My Bid =_$, or Buy it Now = $18 Each (Sells for $30) Includes (1) TMC6-HA Sensor and that is all.
#5) Demo HOBO H9 Shuttle Data Transporters H09- 003-08 - Minimum Bid =$18, My Bid =_$, or Buy it Now = $30 Each (Sells for $159) Includes (1) H09- 003-08 HOBO H9 Shuttle Data Transporter - Perfect for collecting the data out in the field for up to 50 of your Demo HOBOs on one Shuttle (Palm like HOBO data storage).
Auction Contact Information
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
email: rich@hobodepot.com
phone: 877-564-4377
web: http://www.hobodepot.com
Technorati Tags: education, probeware, falconphysics
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