The 2-wire method is commonly used as it is the simplest and most straightforward method. In 2-wire, you can get accurate measurements above 100 kΩ relatively easily. For precision measurements with resistances (ohms) below 100 kΩ, 4-wire works more reliably and conveniently than 2-wire. 4-wire requires 4-wire switching and more cabling. You may decide the tradeoff is acceptable, depending on the accuracy versus complexity requirements of your system.
The following figure shows a 4-wire resistance (ohms) measurement, including lead and switching resistance:
Current (amps) is forced through the source leads (HI, LO). As a result, a voltage develops across the resistance (ohms) under test. By measuring the voltage directly across the resistor using the sense leads, the voltage drop of interconnects (RLEAD) is ignored.?
The difference is the "delay time setting". For "STEP", the delay time setting is between each channel. For SCAN, the delay time setting is between a 10-channel turn to another.
It doesn't matter. However, we suggest that you may fix screws for the better measurement. The metal flakes with the screws connect to the chasses ground; as a result, fix screws could reduce the environmental noise and statics.
The USB supports up to 127 different devices. Additional USB devices are connected through
hubs in a tiered star topology which consists of multiple USB peripherals connected to a single
USB hub and multiple USB hubs connected in a chain, one to another.
Yes. We provide a free stand-along program"AP" for customer to transfer the measured
data from M3500A to PC even they do not install 「MicrosoftR Office」.
M3500-opt01 Multi-point Scanner Card is not allowed of direct current measurements; however, on-card shunt resistors can be installed for channels 1 and 6 to allow for indirect current measurements.
The figures below show the typical configuration for current measurements.
The current through each shunt resistor can be calculated as follows:?
I= current being determined?
V= voltage measured by multimeter?
R= shunt resistance value?
Instead of manually calculating current, set up a MX+B math calculation function. (M=1/R and B= 0.). The M3500A will then display the actual current value.?
Note: If there are two devices under test, the value of User-installed Shunts(R) have to be the same.
. M3500A supports 7 types of Thermocouple: E, J, K, N, R, S and T. Via thermocouple adapter, user must measure a known temperature junction (T1) and then modulate the value of reference junction according to the result. The value of reference Junction must be stable, so that user can measure an accurate temperature.
How to modulate the value of reference junction for thermocouple measurement:
1. Configure the thermocouple type and unit. Pressing CONFIG >> SHIFT >> TEMP(TCOUPL), and then using PREV and NEXT to select the type and unit.
2. Measure a known temperature junction (T1). The result of the measurement is Tm.
3. Modulate M3500A reference junction to make Tm=T1.
Reference junction modulation：
Panel:
CONFIG >> SHIFT >> TEMP(TCOUPL) >> NEXT >> NEXT >> SIMULATE >> ENTER
Pressing 「PREV」 or 「 NEXT」 and 「RANGE」 to modulate the reference junction.
PC remote control Command:
「:TCO:RJUN：Sim value」
Example:
If the reference junction=23.0°C, T1=30°C，Tm=25°C, we should modulate the reference junction to 28.0°C to make Tm=30°C. ?
USBTMC 是 USB Test & Measurement Class 的簡稱。只要含有 USB 介面的儀器符合 USBTMC，在不受任何平台和環境的限制下，即可透過 VISA 驅動儀器，並與 PC 進行通訊。換言之，透過 VISA 對 USBTMC 儀器的控制，與透過含 GPIB 介面儀器的控制，其程序與操作是一樣的。
USBTMC(USB Test & Measurement Class)：USBTMC是建立在USB之上的一種通訊協定。只要含有 USB 介面的儀器符合 USBTMC，在不受任何平台和環境的限制下，即可透過 VISA 驅動儀器，並與 PC 進行通訊。透過 USBTMC 及 USB488 協定，能像控制 GPIB 一樣來控制 USBTMC 且同時支援觸發 等其他 GPIB 的命令。使用 USBTMC 的好處是不需要增加任何介面，也不需要重新編寫程式， 經搜尋儀器後，只要使用符合 USBTMC 協定的 VISA 層，就可透過 USB 來實現 GPIB 的通訊 方式。只要作業系統上安裝 NI-VISA 3.1 以上版本的驅動程式後，USBTMC 的裝置就能夠被 識別且可以使用。
(參考網站 http://digital.ni.com/public.nsf/allkb/044fa220f32774ed86256db3005850ca)
Please set trigger time by pressing the buttons on the front panel.
MENU -> NEXT to TRIG -> ENTER -> NEXT to DELAY -> ENTER. The problem is regarding the time setting
of trigger delay. Then, please in the PT-TOOL software input the remote control command for speeding up
the scan capability. "TRIG:DELAY 0.1".
Please do the warm-up step in two hours for solution. Because the temperature of the instrument
and the adapter must be the same so that measuring the value will be stable. To do the warm-up step can
let the instrument and the adapter with the same temperature.
Please confirm the version of NI visa is 3.1 or upward. If it is incorrect, please refer to our User
guide in CD we enclosed with the Instrument to link the NI website and download the correct NI Visa
to operate.
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"POWER OFF"
Figure 2-13
igure 2-14
"POWER ON"
