MAUTECKK MT6685 Femto/Picoammeter(MAUTECKK offers custom Picoammeter)

Low-priced version of MT6685 Femto/Picoammeter,price is around 1200USD/pcs. (MAUTECKK offers custom Femto/Picoammeter)

REMARK:  We offer Femto/Picoammeter with multiple interface versions, such as USB, BNC, 485, SMA interface, etc.


MAUTECKK MT6685 Femto/Picoammeter (MAUTECKK offers custom Femto/Picoammeter), low price(price is around 1200USD/pcs), short delivery time.

Our company can also provide microcurrent and microvoltage measurement and testing solutions according to your needs.

The MT6685 Femto/Picoammeter has the following features,

1. low price(price is around 1200USD/pcs, The price is about half of USA KEITHLEY 6485, KEYSIGHT B2981)

2. the minimum measurement can be as small as 0.01PA picoamps

3  We have two standard models with capacities of 0.5PA to 10mA and 10pA to 10mA. We can also customize the Femto/Picoammeter to suit your needs. 

4. it can replace USA KEITHLEY 6485, KEYSIGHT B2981 AND OTHER MODELS OF KEYSIGHT (AGILENT). Mature products, has been applied in the market thousands of units. The performance reaches the standard of imported brands.

5. Low price, high precision, fast response, wide range, ultra-portable


  1  Functional Overview

Shanghai MAUTECKK's MT6685 Picoammeter is a high-precision portable ammeter specially developed for measuring weak current. The product has the characteristics of ultra-low test voltage drop, low noise and small error. A wide range of positive and negative current measurements from pA to mA can be achieved. This product is suitable for machine weak current signals generated by various sensors such as photodiodes, electrochemical sensors, bioelectricity, ion beams, electron microscopes, etc.

The MT6685 is compact in size, uses a single USB for power supply and communication, and is easy to carry and use. An isolation scheme is used internally to avoid interference. Shanghai MAUTECKK has developed an easy-to-operate PC application software, and can provide a variety of serial communication interfaces to facilitate the secondary development of users. MT6685 can also realize advanced setting functions such as automatic or manual gain, clearing, power frequency filtering, and reading speed.

In addition to the standard USB interface, the product also provides RS232 or RS485 communication options. In addition to communication, the signal output also provides current direct-to-voltage analog signal output for high-speed sampling, or analog signal output to meet various application needs.

     Figure 1. Typical application of MT6685 Picoammeter



 Figure 1. Typical application of MT6685 Picoammeter


2 Controller Features





Sampling frequency

DC ~ 50Hz

Analog output

0-±1.5V, Resolution 0.03%

Test terminal voltage drop


Operating temperature

15°C to 35°C, <70% RH,


Storage temperature

0°C to 50°C, <90% RH

Dynamic Range


Measuring range





1% + 500fA



0.5% + 5pA



0.2% + 50pA



0.15% + 500pA



0.15% + 5nA



0.15% + 50nA



0.15% + 500nA



0.15% + 5μA

data transmission

USB 2.0

powered by

powered by USB(optional for RS232、RS485 )







3 Communication protocol

3.1 Communication interface

  • Using isolated communication
  • Compatible with 485 (DB9) or USB (square head) virtual serial port communication mode, baud rate 115200
  • 485 and virtual serial port can only have one communication at the same time

3.2 USB Virtual serial port driver download address


3.3 Serial port debugging software and parameter settings

Whether it is a USB analog serial port or 485, the serial communication command is used

after connecting to the computer

Serial debugging assistant 

3.4 Serial port instruction description

With acknowledgment communication, each command returns a value


  • InquireID  :
  • Command function: query the number of the device
  • Send format: [:]:id?:
  • back to example: [:]:id?:PA81R02_SN:PA81_0001


  • Read the picoammeter value:
  • Command function: used to return the current value read by the picoammeter
  • Sending format: [:]:msr:pavl:00:00:
  • Example of return: [:]:msr:pavl:00:03: 5.46842e-6 [current picoammeter channel 00,

gear 3,  the measured current value returns the ampere value of the current in the

format of 7.5e]

  • Other instructions: none
  • Set the picoammeter gear:Ø
  • Command function: It is used to fix or manually set the gear position of the picoammeter (automatic gear when powering on), it is recommended to use the automatic gear position for normal test stable signals, and the manual gear position is recommended for signals with a relatively large test fluctuation range.
  • Example of sending format: [:]:set:pagn:00:03: [Set picoammeter channel 00 gear 3]
  • Example of return: [:]:set:pagn:00:3
  • Other instructions:
  • The range of gears is 0~7, if the setting range is exceeded, it will be automatic gear
  • Clear the picoammeter:
  • Command function: used to set the zero position of the picoammeter, each gear is cleared individually
  • Example of sending format: [:]:set:pacl:[Picoammeter reset, regardless of channel]
  • Example of return: [:]:set:pacl:00: G0ClrVlu: -32.055G0ClrVlu: -32.055
  • Other instructions: none
  • Set the power frequency filter parameters (calculation period):
  • Command function: When testing weak signals, you can set filter parameters to remove low-frequency interference such as power frequency to ensure the accuracy of the test.
  • Example of sending format: [:]:set:PAFT:00:50:【Set the calculation period of picoammeter filter to 50Hz】
  • Return example: [:]:set:paft:01:PicoAmpFilter is: 50 HZ
  • Other instructions:
  • The set value is the cycle of the internal calculation and update of the measured value of the picoammeter, such as 50HZ, which means that the average value is calculated internally with 20ms [50Hz] as the measured value
  • For mainland China, it is recommended to set it to 50/N, (N=1,2,5,10), such as fast shifting, set it to 50, it is necessary to test weak current or reduce the fluctuation of the measured value, it can be set to 5 or 10

4  PC software

In addition to realizing the basic functions of the above communication protocol, the host computer software also has its own curve display and data export functions. The interface is as follows:

         Figure 2. MT6685 application 

  • "Detector reset" is used to calibrate the zero position. After clicking clear, the meter needs about 15s to clear, after clearing, the dialog box "clearing completed" will pop up, and then the data can be read normally.
  • "Start reading" is used to read or stop reading data
  • "Rate" drop-down dialog is used to select the sampling rate, which can be selected from 0.1Hz~10Hz
  • "Auto Gain" button will automatically select the appropriate gear between 0~7 gears by the picoammeter according to the current current value. It is recommended to select the option to change.
  • "Set Gain" is used to manually set the gain, and the selection box below is used to select the manually set gear. It is recommended to use this function when the test current of the gear picoammeter changes rapidly, which may cause frequent shifting.
  • "Display seconds" is used to display the number of recently sampled data in the graph box
  • Export data can export data in csv format

5   other

In addition to portable picoammeters, our company also has picoammeter measurement modules for easy integration into the device. The picoammeter measurement module supports multiple modules in parallel for multi-channel testing.

6   Many customers around the world are using our products, and some of our customers are as follows.

If you have any questions, please feel free to contact us, thank you. 


Contact person:Sherwin Law

Mobil: +86-13524766010

Tel: +86-21-34316920

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Skype: 8613524766010


微信/Wechat: 13524766010

Shanghai MAUTECKK Electronics Technology CO., Ltd

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