New Sensor Location

[malc-c]

Hi guys, long time since I posted here, hope everyone had a good Christmas etc ?

Over the Christmas holidays one of our neighbours lost their felt roof due to the stormy weather on Christmas eve. My sensor array was on a pole fixed to the garden shed, which has now become somewhat shielded by vegetation but still recorded a gust of 39.4 MPH. But it was obvious by the damage that the true wind speed was a lot higher, so with the help of a friend who had a long ladder we relocated the array and sender to the house. I had to extend the cables, so used normal telephone extensions, but these need sealing against the wet, and to build a Stephenson screen around the temp sensor, but at least now I'm getting unobstructed wind runs (other than the chimney).

I'm not happy with the sender unit being so high up, but as we have a footpath for access to the allotments behind us had no choice to mount it out of reach to ensure no casual act of vandalism could take place.

It still bugs me that these units are supplied with such short cables...

[hills]

good job!

I see from your webpage we share an interest in rc helis, but you don't seem to share my fear of snakes!

[malc-c]

LOL - the snakes are harmless - they love giving people cuddles

Sold most of my RC helis a few years back, but still find them interesting - one of my co-workers where I used to work had one of those small contra-rotating helis and was having problems getting that off the ground (why I don't know as they fly them selves) - Love the look on his face when I took the controls and slung it around the office

The station is performing Ok, but still have concerns over the ext leads, and how best to protect them in wet weather. Would be nice if the unit came with longer leads or better still, fit RJ11 connectors to the rain and wind direction units so you could interchange the cables for longer ones !

[OldZack]

Re the Stephenson screen for the sensor unit. This is a cheap, easy and effective solution. Wickes's sell lengths of soil pipe, intended to be cut to fit between the toilet bowl and the O/g sewer pipe. It's wonderful stuff! It comes in a length of about 900mm, is about 3mm thick and the inside of the pipe is about 150mm wide. It's bright white and tough and will fit over the sensor unit leaving about 12mm clearance all round! It's just what we need. Hack off whatever length suits your needs and drill a lot of 10 - 12 mm holes in vertical rows all round. That's the hardest part. Now use your ingenuity to suspend your new and glorious white screen over the sensor unit and suddenly those ridiculous temperature figures pushing up into the mid thirties are a thing of the past and you are much closer to measuring true air temperature. All done for about 7 quid.

Good luck!

Garth

[malc-c]

Thanks for the tip.

I'm looking at moving the main temp/humidity/sender unit as it's too high up, but will have to move it to within our garden as it could get vandalised, and this suggestion will help as the new locations will be in direct sunlight in the summer.

Anyone know the limit of extending the cables from the wind and rain sensors ??

[AllyCat]

Hi Malcolm,

There's virtually no limit on extending the rain cable, but you might find that extending the wind cable of an "old" version of the 1081 causes spikes or even major errors in the external temperature. For Maplin stations, "old" means about two years, for others the presence of a thermistor in the transmitter (blue "bead" in the third post here) probably indicates that it's the old, shared A/D converter type. Generally, a "flat" (ribbon) extension cable is likely to be better than a "twisted pair" (e.g. CAT5) type.

Of course you must also make sure that all connectors are well water-proofed.

Cheers, Alan.

[malc-c]

Thanks for the info Alan... That's part of the problem, using 5m ext cables the connectors get full of water and I'm loosing wind and rain data. I have a crimp tool so was looking at getting a 50m reel of four way cable and extending the cables, so they would be hard wired into the sensors, and connected to the main unit in the same way as using the original cables. That way I could bring them out at right angles as per the image below.

The sender is quite new. My original unit was purchased in 2009, and whilst I've had no issues with the sensors, the pairing of the sender and base unit failed and couldn't be restored, even after lots of suggestions from forum members. As Maplin had these on offer for £59 and I had the cash I purchased another kit, but only used the sender and touchscreen unit...it was all working well until I moved it and used the extension leads. I've not looked to see if it uses a thermister as a sensor, or the newer equivalent. Fingers crossed it will all still work by the time I've removed the internals to solder the ends of the wires to the sensors !

[malc-c]

Well after several days of rain the weather was kind enough to give us a window in which to sort the station out.

I removed the old wind sensor array from its old position on the shed at the rear of the garden, and opened up the wind speed sensor. I removed the old cable and soldered one end of a 100m drum of four cable purchased earlier this week (around £8 plus delivery and VAT - a lot cheaper than all these phone extension cables I've purchased !!) to the PCB, . It was tested and worked well over the full length of the drum, which was encouraging given the length of run I was looking at.

My friend Steve turned up with his ladders and took the sensor array up with him. He then removed the array at the top of the pole and fitted the one modified, securing the cable with ties. The cable was then secured all the way down using cable ties to the existing aerial / sat dish cables, and then back to the rear gate. I relocated the old rain sensor to the top of the wooden shed (seen on the left of the picture above) as it was in a similar position for years on a shed at the back of the garden so should give similar results. The main sender and temperature unit was also secured to the shed around 4' off the ground. The sender is sheltered from direct sunlight by a large conifer tree directly in front ( the sender is now south facing), thick bamboo to the left (East through to south) and the the house (to the west). Having the sender this high means we get better temperature readings as it's not 15 feet in the air, and I can easily replace the batteries when required. The new cable was then run round the shed and an RJ11 crimped on to the cable, and I'm pleased with the result.

I'm so pleased to have a full working weather station back up and running. The wind sensor has recorded a gust of 39.8mph already today, and it will be interesting to see what happens in the days to come given the forecasts