Logging Lightmeter & Multimeter with Scope?

[Cones]

Hi,

I am looking at getting a lightmeter and possibly a Multimeter with a PC interface for logging LED Runtimes.

I see that I can get a Extech lightmeter that has on board storage.
Lightmeter with Datalog

They also make a 5MHz scope meter with a PC interface. This could be useful for playing with some LED driver circuits so I can see what is going on.

Multimeter with Scope

I see that Extech also make a lux multimeter adaptor to use with a multimeter. This could be used with the above or my existing Fluke 179.

Is anyone using datalogging hardware so you can take multiple inputs at the same time? I.E. Current, Voltage, Lux, Temperature?

What are everybodies thoughts on these? Any other suggestions?

I am in the UK and anyone with a suggestion of the best place to get these from would be welcome.

Many Thanks

Mark

 

[djpark]

That multimeter with scope looks nice and wish to get one of those someday.

I am using a PIC12F675 based homemade logger which gets 4 analog input (0-5V) and send the data to PC via RS232 every second. 3 inputs are used to measure the battery voltage or led voltage and 1 is tied to TPS101 to get the brightness.

It is simple to build and uses power from the serial port directly. But it has relatively low input impeadance and has only 10bit resolution (though I feel reasonably sufficient for cpf logging).

My target design includes ADS7825 16bit ADC with OP amp and also MAX471 to measure the current flow with internal 35mohm sense resistor, external eeprom running on a LI battery for self contained logging and trsnsferring to PC on demand.

-- dj

 

[Cones]

/ubbthreads/images/graemlins/bumpit.gif

Thanks

Mark

 

[LED_ASAP]

djpark

Can you point us the link of your home-made logger? I'd love to get something like that /ubbthreads/images/graemlins/bowdown.gif

 

[djpark]

I don't have a ready link for it.

I will post HOWTO with the circuit, pcb and firmware here soon.

-- dj

 

[Doug Owen]

If you really want to dabble with DMM 'scopes' how about Vellman 'scope' ? Half the bucks.....

Doug Owen

 

[Cones]

Thanks for the suggestions so far.

Keep them coming!

I have found this

DMM with RS232

At £46 + VAT (17.5%) it seems a very good deal and the software exports to excel.

The Fluke 189 + Software is around £338 + VAT (17.5%)
Ouch, It does log 100 readings without a PC connected though.

I think this is what Don uses, looking at his runtime graphs.

Thanks

Mark