Microsensor MDM4901FL User manual

MDM4901FL
Operation Manual

Our company reserves the modification right for this operation manual
due to renovation of production technology and craftwork. If some
information is changed, no more notice will be edited.
Please pay attention to the latest version.
Our company also reserves the right of final explanation for this manual.
Version: V1.0

Thanks for your using products from MICROSENSOR. MDM4901FL
piezo-resistive differential pressure transmitter is one of precise
instruments. We suggest you to read this manual carefully before use.
1 Introduction
MDM4901FL piezo-resistive differential pressure transmitter is a
differential pressure measurement device with compact size. The
transmitter using a differential pressure sensor and special amplified
circuit, through stability and reliability experiments, can provide
standard 2-wire 4mA～20mADC and 3-wire 0/1V～5VDC 、0mA～
10mA/20mADC signal output by external power supply 24VDC, as well
zero and span compensation in the wide temperature range.The parts
being contacted with the medium are the stainless steel and EPDM.
The differential pressure transmitter can be used in vary industry
processing control and differential pressure, flow and level
measurement, etc.
2 Specifications
Pressure Range: 0 mbar ~ 350mbar…35bar
Overpressure: positive pressure:≤ 2 times FS
negative pressure is not allowed
Maximum Static Pressure: ≤200bar
Pressure Type: differential pressure
Accuracy: ≤±0. 5%FS (Static pressure effect: ±0.05%FS/1bar)
Long-term Stability: ±0.5%FS/year (≤2bar)
±0.2%FS/year (>2bar)

Power Supply: 15V~28VDC
Output: 2-wire 4mA~20mADC
3-wire 0/1V~5/10VDC，0mA~10/20mADC
Operation Temperature: -30℃~80℃（4-pin Plug、M12×1 Plug）
-20℃~70℃（cable material: PE, PVC）
-20℃~80℃ (cable material: PUR)
Storage Temperature:-40℃~120℃ -20℃～85℃（Cable）
Response: ≤1ms
Insulation: 100MΩ， 50VDC
Housing Protection: IP65
3 Outline Construction and Installation
Unit:mm
3.1 Construction and Mounting Dimension
32
58
8 8
SW22
(50)
?19
（150）
G1/4 female G1/4 female
30 40
27
SW22
32
58
88
(115)
30 40
27
SW22
G1/4 female G1/4 female
SW22
Fig.1 Fig.2

32
58
88
M12×1
（115）
30 40
27
SW22
G1/4 female G1/4 female
SW22
Fig.3
3.2 Installation
3.2.1 Attentions before installation:
a) The operating pressure of measuring medium is no more than
the static pressure of transmitter;
b) The differential pressure of measuring medium in the worksite is
no more than the maximum pressure.
c) For positive and negative pressure balance and convenient
repair, we recommend to use tri-valve （such as J23SA）to connect with
the leading tube, to prevent one-side overpressure destroying the
transmitter. Or the customer can buy the leading tube and tri-valve from
our factory. Tri-valve operation method can see appendix “Tri-valve
Operation Menu”.
3.2.2 Installation Method
a) The recommended method is to see Fig. 4.

Fig. 4
b) Installation notes:
1) To prevent the installation position from affecting zero output
signal, the transmitter can be installed horizontally on the tube
and the plug could be installed vertically up.
2) Pay attention to whether the measured medium is consistent with
the transmitter structure material.
3) Pay attention to the measuring medium is compatible with the
construction material or not.Notice the positive(“＋”) and
negative (“－”) mark on the pressure ports while connecting the
actual pressure direction corrrectly.
4) The transmitter should be installed in the low temperature
gradient and low temperature fluctuation place, to prevent
vibration and shock.

5) The protection of transmitter is IP65。
6) Prevent leak, friction and temperature difference error, to prevent
dregs settling on the tube affecting the diaphragm.
7) The transmitter has been calibrated when out of the factory, the
customer can operate the transmitter without calibration, but
checking the installation and electrical connection correct or not is
necessary. The transmitter can work when excitation is
connected, but the signal output is more reliable after 30 minutes.
8) Ban to pulling the cable violently, and to prevent the diaphragm
damaging don’t poke the diaphragm with metal still objects.
MDM4901FL piezo-resistive differential pressure transmitter
allows the customers to adjust the zero and Span output signals
while you own a standard pressure controller. While adjusting, for
the transmitter with plug connection, remove the socket on the
top of housing (take care not to break the cable), then trim “Zero”
and “Span” buttons to adjust. For the transmitter with cable
connection, you need to use a wrench slightly screw the cap and
you will find the Zero and Span calibrators on the top of housing.
Restore them when finish.
If the transmitter is fail to work, the customer should contact with
factory checking the reasons, and return to factory for repair.
Caution：do not poke the pressure-leading hole with metal wire or
something hard; and do not pres
4 Electric Connection
4.1 The transmitter is connected with the outside circuit

through plug or special cable.
The pin arrangements of socket are to see Fig.5, and pin definitions
are as follows：
Table 1
Fig.5
The electric definitions of cable are as follow：
Table 2
Cable 2-wire 3-wire
Red +V +V
Black OV/+OUT GND
White Null +OUT
The electric definitions of M12x1 Plug are as follow
Table 3
Fig. 6
4.2 Electrical connection method is indicated as follow
Pin 2-wire 3-wire
1 +V +V
2 OV/+OUT GND
3 Null +OUT
Pin 2-wire 3-wire
1 +V +V
2 Null GND
3 OV/+OUT +OUT
1 2
34

4.2.1 4mA~20mADC(2-wire)
P
I
P/I Transmitter
P
Input 0V/OUT
+V +
U
DC current
+
-
-
R
Load
I
4mA ～ 20mA
Fig. 7
4.2.2 0/1V~5VDC(3-wire)
P
I
P/U Transmitter
P
Input +OUT
+V +
U
DC current
+
-
-
U
0/1V ～ 5V
GND
Fig. 8
4.3 Plug connection Operation Method：
a) If the plug has been connected with transmitter, loose the central
bolt on the top of plug with little screwdriver and pull out the plug
from transmitter.
（caution：do not take out the socket on the transmitter to
protect it）
b) To disconnect the plug, please take out the central bolt on the

top of plug, then turn the plug to the bottom and insert a little flat
screwdriver into a corner signed “Lift” and give a force. The plug
core will be disconnected with housing.
c) To connect the cable, put the cable through the cable jack and
connect the wires with terminals on the plug core correctly (the
connection terminals are signed with clear numbers). Please
choose Φ4.5mm~7mm shield cable and connect the cable
reliably to prevent short circuit.
d) Pull the cable slightly and push the plug core into housing (a
rattling sound could be listened), then screw down the
cable-fixed nut.
e) To remove the cable, loose the cable-fixed nut to relax the cable,
and operate as Item2 to disconnect the plug. Take out the cable
from terminals with little screwdriver and pull out the cable from
cable-fixed nut, then renew the connection between plug core,
plug and socket.
Caution: renew the rectangle-ring to the pre-mounting situation in
order tomaintain the protection class when connect plug
and socket.
5 Unpacking、Components and Storage
5.1 Unpacking
a) Be sure the package is completed, and the package should be put
as the sign “UP”.

b) Be sure unpacking carefully, and prevent damaging instruments or
accessories. Pay attention to the housing jacket and rubber
bushing of transmitter cable.
5.2 Enclosed
The transmitter should be enclosed when out of factory：
When out-factory, the transmitter should include:
MDM4901FL piezo-resistive differential pressure transmitter 1pc
Electrical connection plug (insert supplied) 1pc
Cable (cable supplied) 1.5 meter or based on order
Product operation menu 1pc
Product certificate of quality 1pc
Quality following card 1pc
5.3 Storage
The transmitter should be stored in dry ventilate room, ambient
temperature -40℃~120℃ -20℃～85℃（Cable） and the relative
humidity≤85%, no corrosive substance in the room.
6 Responsibility
Within one year from the delivery date, we shall repair or replace the
instrument with any quality fault caused by material parts or our
manufacturing technique free of charge. For non-quality malfunction
during user’s operation, we are in charge of repair. But the material
cost and the shuttle transportation fees should be borne by users.