The ST-140D differs to the ST-140 in that it has  data logging feature with a memory capacity from 99 readings to 9999 and possesses a user-friendly USB interface.

The ST-140D can measure velocity and displacement  over a frequency range of 10Hz to 1KHz and measure acceleration from 10Hz to 1KHz in LO mode and 1KHz to 5KHz in HI mode. The measuring modes include RMS and peak for acceleration and velocity as well as peak-peak for displacement. The ST-140D has hold and max hold functions in addition to auto power off with disable.

ST-140D Features:

• Acceleration, Velocity and Displacement measurement.
• High sensitivity probe head for accurate measurement.
• Provides long and short probe head.
• Frequency meet ISO 2954-2012 Measurement
• LO range: 10Hz-1KHz
• Hi range:10Hz-5KHz.
• Data logging with 9999 records capacity.
• Auto power off with disable function.

Tenmars ST-140D Vibration Meter Description:

Wide frequency range of 10Hz to 5KHz
Acceleration, velocity and displacement measurement
Meets ISO 2954 sensor for accurate measurement
Vibration sensor with magnetic adapter on 1.2M cable
Frequency Lo range :10Hz~1KHz meets ISO 2954 measurement, Hi range : 10Hz~5KHz
Stores 99 records manually
Record /Recall MIN (ST-141),MAX readings
Offset adjustment used for zero function
Auto power off with disable function
Resolution: 0.1m/s², 0.01g, 1ft/s², 0.1mm/s, 0.01cm/s,
0.01inch/s,0.001mm,0.001inch

Tenmars ST-140D Vibration Meter Specifications:

Measurement frequency range	Acceleration	10Hz～1KHz (LO)；10KHz～5KHz (HI)
	Velocity	10Hz～1KzZ
	Displacement	10Hz～1KHz
Measurement range	Acceleration	0.5～199.9m/s2
	Velocity	0.5～199.9mm/s
	Displacement	0.005～1.999mm
Function	Acceleration/Velocity	RMS, Peak, Max Hold, Hold
	Displacement	Peak-Peak, Max Hold, Hold
Accuracy		± (5% reading ±5 digits),ref. 79.4/158Hz, 23°C,<80%RH
Dimension		156x73x35 (LxWxH)
Power supply		1.5V AAA alkaline battery x 6
AC adapter		AC 100~240V to DC9V/0.5A
Data stored		9999 records