CED M2 Chrono Issues

[Bkluke]

I have a new CED M2. I am getting readings that are about 200 fps slower than they should be. I shoot a 6 Dasher with 32.5 to 33.5 grains of RL 15, at a temp of 70, I should be over 3000 fps but I am not. This is with the IR screens. Has anyone else had any trouble with these units?

 

[swehrman]

Have you tried it without the IR screens turned on? I've had issues with my original CED when using the IR screens and it was very sunny out. The following is from the CED home page FAQ.

Q
Can infrared screens be effected by sunlight or indoor lighting?

A
It is possible for very bright sunlight or strong fluorescent indoor lighting to interfere with the use of infrared screens making it hard for the sensors to detect a shadow or a break in the beam itself. If this occurs, simply change the position of the screens to a shady,less sunny) location or place a piece of solid or dark cardboard over top of each screen. If the sun is very bright, it turning off the infrared and use the screens with natural sunlight only as the diffuser. Infrared screens function with their own light source, which allows them to be used under cover, indoors, during cloudy or overcast days, or in the evening when there is insufficient sunlight or no sunlight at all.

-- Scott

 

[ronemus]

I glued a piece of cardboard to the top of each IR source to prevent the screen from getting too much light. Running that way I've never had a problem getting the right velocity, unless the battery was low. That can be very annoying as the system continues to respond to the keypad, but the screens don't register shots. If in doubt, the first thing to do is put in a fresh battery.

 

[SooStan]

I second the fresh battery issue. Mine drains batteries pretty fast when the speaker is on. I don't use the speaker anymore.

 

[Sako6555]

I have seen an issue when setting-up my chronograph. Each time I set up the chrograph, it will read step difference in velocity compared to the same load shot on another day. I can only attribute this to the variability in clamping the sensors to the arm. My guess is a small difference in the effective length between the sensors has a big effect on teh mean velocity measured.

Anyones else seen this ? Or am I just "lucky" ???

Sika

 

[DRNewcomb]

I have a different CED M2 issue. The previous time I used it I got E0 and E1 errors, depending on which sensor I used for stop and start. I brought it home, checked and replaced the 9v battery (it was low) and then ran a flashlight test on the sensors. It checked OK. Last week I took it out again and got E0 and E1 again. Checked again with the flashlight test but this time I spent the ~$48 to order a new sensor.

I'm curious if anyone has ever had a similar situation where a CED M2 would give E0 & E1 errors but pass a flashlight check?

 

[jimcasey01]

I have a different CED M2 issue. The previous time I used it I got E0 and E1 errors, depending on which sensor I used for stop and start. I brought it home, checked and replaced the 9v battery (it was low) and then ran a flashlight test on the sensors. It checked OK. Last week I took it out again and got E0 and E1 again. Checked again with the flashlight test but this time I spent the ~$48 to order a new sensor.

I'm curious if anyone has ever had a similar situation where a CED M2 would give E0 & E1 errors but pass a flashlight check?

I had the same issue when I received my unit new. I was using the standard sensors. Sent both sensors to CED after a few telephone conversations and they quickly replaced them, no questions asked. They stated that the sensor cord pins were damaged, had probably been damaged in transit. Recently tested my unit against a LabRadar, results were mostly +/- 3 fps, with a couple of readings +6 fps. More time consuming to set up than the LabRadar, but seems to be very accurate and much cheaper. I did notice that the higher the sun was in the sky that my readings, compared to the LabRadar, increased in speed. Early morning CED readings were lower than LabRadar, and read same as or higher as the sun reached 90*.

PS a few of my readings were as much as +10 fps over LabRadar. My pre-coffee memory is often faulty.

 

[DRNewcomb]

I had the same issue when I received my unit new. I was using the standard sensors. Sent both sensors to CED after a few telephone conversations and they quickly replaced them, no questions asked. They stated that the sensor cord pins were damaged, had probably been damaged in transit. Recently tested my unit against a LabRadar, results were mostly +/- 3 fps, with a couple of readings +5 fps. More time consuming to set up than the LabRadar, but seems to be very accurate and much cheaper. I did notice that the higher the sun was in the sky that my readings, compared to the LabRadar, increased in speed. Early morning CED readings were lower than LabRadar, and read same as or higher as the sun reached 90*.

Thanks. I've had my M2 for a few years now, so I didn't even ask about warranty replacement. Maybe I should have. I also just updated my copy of RSI Shooting Lab and notice that they now support BC calculations from LabRadar data. That is a HUGE step for the hobbyist, even if the radar range is limited.