不如这样吧,
楼主既然有这么一个贵价好宝贝,
就造福一下坛友,帮忙给坛友们校正万用表吧,邮费贵客自理,楼主费点时间、精神而已。
pm连接。谢谢。
哪天我去捡一个玩玩
我有两个
自己备料做的
包块泡沫就恒温、恒湿了?
包块泡沫就恒温、恒湿了?
xll 发表于 2010-3-3 12:13 http://www.shoudian.org/images/common/back.gif
LTZ1000ACH 内部有恒温电路
包泡沫只是为了增加热阻
只有流口水的份了~{:1_238:}
这价格可以买好几个表了,哎。
基准的漂移是年1PPM之内
映呈 发表于 2010-3-3 09:05 http://www.shoudian.org/images/common/back.gif
恐怕300元买不到这样的东西
查了一下资料,1ppm是有可能的,但电路和其它方面应该比较难做:
LTZ1000 and LTZ1000A are capable of providing ultimate
voltage reference performance. Temperature drifts of
better than 0.03ppm/°C and long term stability on the
order of 1μV per month can be achieved. Noise of about
0.15ppm can also be obtained. This performance is at the
expense of circuit complexity, since external influences
can easily cause output voltage shifts of more than 1ppm.
Thermocouple effects are one of the worst problems and
can give apparent drifts of many ppm/°C as well as cause
low frequency noise. The kovar input leads of the TO-5
package form thermocouples when connected to copper
PC boards. These thermocouples generate outputs of
35μV/°C. It is mandatory to keep the zener and transistor
leads at the same temperature, otherwise 1ppm to 5ppm
shifts in the output voltage can easily be expected from
these thermocouples.
1楼的基准设备,估计能做到 万分之一 的稳定度。
PM地址..........
也流行烧基准了
PM地址..........
move2top 发表于 2010-3-3 17:54 http://www.shoudian.org/images/common/back.gif
PM 了,其实用我的标题后面文字,TB搜一下,应该能找到!
再来个约瑟夫森量子电压基准比对一下{:1_217:}
比MAX6350应该高级 楼主米人{:1_231:}
3055实验室的产品?