Radiant X4: A LPM for the masses at Illumination Supply!

[RYDorDIE278]

are these still available for $100?

 

[ARG]

They are back ordered at the moment, but should be back in stock soon.

 

[kaunak]

It looks like a good deal to me. The only thing I did notice was that there's no information on here or the website which lists an accuracy spec for the unit.(e.g +-5%) Do these meters undergo some accuracy/calibration testing before shipping, or are they just shipped as is? Sorry if this has been answered already

 

[ARG]

It looks like a good deal to me. The only thing I did notice was that there's no information on here or the website which lists an accuracy spec for the unit.(e.g +-5%) Do these meters undergo some accuracy/calibration testing before shipping, or are they just shipped as is? Sorry if this has been answered already

Hobbyist meters (TEC based) often don't have an accuracy spec associated with them because of the longer response time.

http://laserpointerforums.com/f70/lpm-response-time-who-needs-84428.html#post1221446
and this post specifically
http://laserpointerforums.com/f70/lpm-response-time-who-needs-84428.html#post1222237

 

[kaunak]

Hobbyist meters (TEC based) often don't have an accuracy spec associated with them because of the longer response time.
and this post specifically
http://laserpointerforums.com/f70/lpm-response-time-who-needs-84428.html#post1222237

Understood. I love the graph that was posted by Trevor, very valuable info there. I'll try and reword the question more accurately. Would it be alright to expect a hobbyist TEC meter such as the X4 to have +- 5% accuracy when measuring a stable diode output after the sensor has warmed up?(after 45+ seconds) I know when using lasers with widely variable power outputs TECs are almost useless for an accurate reading, but can you expect an accurate +- 5% reading with a stable output laser after sensor lag is taken into account with units such as the X4? That was really my question, it just took a lot of typing to ask properly. Only asking because of Paul's post about it reading 88% under his laserbee( I guess he actually meant 12% under)

 

[ARG]

+/- 5% is typically what you can expect from hobby LPM's in my experience, with a stable diode laser.

As for paul's spec there is a lot of moving parts there. He tested it with battery powered DPSS builds measured 185mW on the LB and 165mW on the X4.
Handheld/battery operated lasers typically are not good sources for calibration as they will heat up and drop in power over time, even with long duty cycles. Plus DPSS lasers are inherently unstable.
All thermal meters (even professional ones) can swing by a few milliwatts if the ambient temperature is not constant, or if there are air currents.
Readings to comment on accuracy should be taken with higher power lasers, in the 1W area where a few milliwatts of heat does not have a large % affect on the readings.

 

[paul1598419]

kaunak, ARG is right. Even though my build is battery powered it uses a great deal of heat sinking and is fan cooled as well, so it is more stable than a pointer. But, when taken into account the fluctuations of the DPSSLs I came to accept the reading of the Radiant as close enough even though my graph with the DPSSL was for 180 seconds and increased during the entire test. That is the response of TEC based LPMs. It is close enough for me to make a reasonable conclusion about the power of the laser. In the higher power single diode lasers you will not see this difference. I hope this was helpful to you. I'd still buy it and I am still happy with it. To get the kind of accuracy you're talking about you will have to spend much more $$$. Good luck, Paul

 

[kaunak]

kaunak, ARG is right. Even though my build is battery powered it uses a great deal of heat sinking and is fan cooled as well, so it is more stable than a pointer. But, when taken into account the fluctuations of the DPSSLs I came to accept the reading of the Radiant as close enough even though my graph with the DPSSL was for 180 seconds and increased during the entire test. That is the response of TEC based LPMs. It is close enough for me to make a reasonable conclusion about the power of the laser. In the higher power single diode lasers you will not see this difference. I hope this was helpful to you. I'd still buy it and I am still happy with it. To get the kind of accuracy you're talking about you will have to spend much more $$$. Good luck, Paul

Thanks for clarifying that. Is there any chance you made measurements of your 1.6w 445 on both of the LPMs? How do they compare at that power range?

 

[paul1598419]

kaunak, yes there was a slight difference, the LaserBee being slightly higher, but it had not been calibrated since it was originally sold over a year before I bought it. And it has a smaller TEC making it about 15-20 seconds faster. I like them both and will keep them both. However, I will also get an OPHIR thermopile and meter when I can justify the added expense. For me, the Radiant is a good deal, they are calibrated before they are sent out. I had some problems getting the data logging up and running, but that was my internet security by Norton doing that. Craig told me that they are +or- 5% and that sounds about right. But, you really can't get too hung up on tolerance numbers with a TEC LPM. It is as accurate as one of those can be. And the price cannot be beaten by anything else on the market. One thing you need to keep in mind is that you need to defocus the beam before you measure high power lasers. My 1.6 watt which actually max's out over 1.7 watts burned my thermopile a little because I forgot that for a second, but not so bad as to effect the accuracy. Good luck, Paul

 

[kaunak]

Yep. The method I use is focusing the laser well before infinity and bringing it in slowly to avoid damage. Damaging the coating isn't fun lol
thanks for the replies

 

[bdgreenb]

mine came into today! Did i miss where it says it doesn't come with the necessary USB chord?

 

[paul1598419]

Yes. you must have because mine didn't come with one either. If you have a printer you can probably use it until you order another one.

 

[ARG]

mine came into today! Did i miss where it says it doesn't come with the necessary USB chord?

In the product description

NOTE: The case is optional and sold separately. A USB-B cable is required for operation.

Makes sense really. Short USB cables are a pain to use with desktops, and long USB cables are a pain to use with laptops. Customer can choose the length of the USB cable they want.

It's a standard USB-B cable. Can get em anywhere these days.

 

[bdgreenb]

yeah i used my external's()HD that is)... this thing is awesome, now to data log

 

[kaunak]

yeah i used my external's()HD that is)... this thing is awesome, now to data log

Glad you found another cable; let us know what you think of the meter/datalogging

 

[csshih]

wow, it seems the forum has become more colorful since I last visited.
any thoughts, concerns, questions about the meter?