Voltcraft DVM230B®Digital panel mounted measuring device, panel meters DVM230B Data Sheet

The module is intended for installation in other devices or casings. It displays direct currents ranging from 0 to 200 mV (DC). 

By means of individual, external circuits, other physical quantities such as direct current or temperatures can also be displayed. 

The measuring units and decimals can be selected. The polarity is automatically displayed. 
A display light is integrated; it can be supplied with the operating voltage or with 12 V/DC.

The power supply of the module comes from an external 9 V/DC power supply unit. The connection is at the back of the module 

in a pin contact strip. You will have to set some soldering links for the selection of the measuring units. There is a data hold 

function to “freeze” the measuring value. The product is only to be used in dry indoor locations. !
For safety and approval purposes (CE), you must not rebuild and/or modify this product. If you use the product for purposes 

other than those described above, the product may be damaged. In addition, improper use can cause hazards such as short 

circuiting, fire, electric shock etc. Read the instructions carefully and keep them. Make this product available to third parties 

only together with its operating instructions.

•  Digital voltmeter module
•  Operating instructions

a)  Persons / Product
•  The device is not a toy. Keep it out of the reach of children and pets.
•  Do not leave packaging material lying around carelessly. These may become dangerous playing material for 

children.

•  Protect the product from extreme temperatures, direct sunlight, strong jolts, high humidity, moisture, flammable 

gases, vapours and solvents.

•  Do not place the product under any mechanical stress.
•  If it is no longer possible to operate the product safely, take it out of operation and protect it from any accidental 

use. Safe operation can no longer be guaranteed if the product:

 - is visibly damaged, 
 - is no longer working properly, 
 - has been stored for extended periods in poor ambient conditions or 
 - has been subjected to any serious transport-related stresses.

•  Please handle the product carefully. Jolts, impacts or a fall even from a low height can damage the product.
•  Also observe the safety and operating instructions of any other devices which are connected to the product.
b)  Miscellaneous
•  Consult an expert when in doubt about operation, safety or connection of the device.
•  Maintenance, modifications and repairs are to be performed exclusively by an expert or at a qualified shop.

If you are not sure about the correct connection or use, or if questions arise which are not covered by these operating 

instructions, please do not hesitate to contact our technical support or another qualified specialist.

a)  Overview of the PCB
All the connections and functional soldering links are made on the back of the 

module.

This  device  can  be  configured  for  different  voltage  ranges,  by 

soldering resistors to the positions RA and RB.

b)  Selection of the measuring unit
Select the necessary measuring unit and the decimal point you need for your measuring section from the 

illustration on the right and set the respective soldering link to “ON”. See example drawing.

c)  Connection of the pin contact strip CN1
The electric connection of the module is done in the pin contact strip CN1. For the respective functions, please refer to the 

following table.

Pin

Description

Function

1

IN HI

Measurement input + (0 - 200 mV/DC)

2

IN LO

Measurement input – (reference potential)

3

VDD

Operation voltage +9 V/DC

4

VSS

Operating voltage -

5

BL+

Display light +

6

BL -

Display light -

7

HOLD

Data hold (connection to VDD)

8

Not assigned

“IN HI” and “IN LO” are differential inputs. They react to the voltage applied and not to the voltage relative to the operating 

voltage. Only a direct voltage may be applied as the measurement voltage. 

e)  Operating voltage “VDD” and “VSS”
The operating voltage (VDD) must be in the range of 9 V/DC (-0.5 V/+1 V). Do not go below or above this voltage, because the 

measuring results would be inaccurate and the module would be destroyed.
If the operating voltage drops below 7 V, the display shows 

 “battery”. Replace the battery immediately or set the input 

voltage to the correct value. 

f)  Display light “BL+” and “BL-“
The display light can be switched on by applying a voltage of either 9 V/DC or 12 V/DC. 

The series resistors for the lights (LEDs) are integrated in the module. 

If the operating voltage is to be 9 V/DC, a soldering link must be set at 

CN2 (see illustration). It remains open for 12 V/DC.

g)  Data-Hold „HOLD“
The value currently displayed is frozen by contacting the “HOLD” (pin 7) to “VDD” (pin 3). The value will remain in the display 

until the contacts are removed.

h)  Internal reference voltage “VR1”
The internal reference voltage is set with VR1. The voltage has been calibrated to 100.0 mV in the factory, it can be adjusted 

according to the respective application, for example to compensate for inaccuracies of external voltage divider resistors.

The contact “LKT” serves for short-term checks of the display segments. When it is contacted, all the segments are shown 

for a check.

For the circuit examples, please refer to the enclosed sheet with the various application circuits..

The LCD shows “1”

The measurement value is outside the measuring range.

The LCD shows “-”

The voltage connected to “IN HI” and “IN LO” is reversed.

Electronic devices are recyclable waste and must not be disposed of in the household waste.
At the end of its service life, dispose of the product according to the relevant statutory regulations.

Operating voltage:

9 V/DC

9 V/DC

Current consumption:

2 mA

2 mA

Measurement range:

0 - 200 mV/DC

0 - 200 mV/DC

Display:

LCD, 1999

LCD, 1999

Measuring impedance:

100 MΩ

100 MΩ

Resolution:

0.1 mV

0.1 mV

Accuracy:

±0.5 % + 10 digit

±0.5 % + 10 digit

Measuring frequency:

3 measurements / sec

3 measurements / sec

Temperature stability:

30 ppm/ ºC

30 ppm/ ºC

Operating temperature:

0 to + 50 ºC

0 to +50 ºC

Display light operating voltage:

9 V/DC

12 V/DC

9 V/DC

12 V/DC

Display light current consumption:

15 mA

18 mA

30 mA

35 mA

Dimensions (W x H x D):

48 x 24 x14 mm

72 x 36 x 14 mm

This is a publication by Conrad Electronic SE, Klaus-Conrad-Str. 1, D-92240 Hirschau (www.conrad.com). 
All rights including translation reserved. Reproduction by any method, e.g. photocopy, microfilming, or the capture in electronic data processing 

systems require the prior written approval by the editor. Reprinting, also in part, is prohibited. This publication represent the technical status at the 

time of printing.