Microsensor MPM426W Series User manual

V1.0
MPM4
26WSeries
Operation Manual

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Thank you very much for selecting Micro Sensor sproduct.
MPM426Wseries Level Transmitter is aprecise instrument, please
take some time toread thisoperation manual very carefully before
using.
1. Introduction
MPM426W series (such as MPM426WPC, MPM426WPF) are
submersiblediffusion siliconelevel transmitters with the fully welded
structure thatare speciallydevelopedfor the petroleum and
petrochemicalindustry.The product utilizes apiezoresistive sensor with
provedlong term stability and reliability and aspecial digital
compensationcircuit that arehoused inarugged stainlesssteel 316L
housing. It offers an integrated structure, supports multiple standard
outputs, andcableoptions of multiplematerial for awide range of
operation temperature. Specifically,MPM426WPF is mostlyused in the
level monitoringof refined oils, such as gasoline, diesel, kerosene, etc.;
MPM426WPC is mostly usedin the level monitoring of chemicals, such
as methanol, ethanol, diesel exhaust fluid (DEF), diesel engine coolant,
etc. Both two level transmitters can alsobe suitable for other monitoring
environments with higher requirements for wear resistance, protection, or
explosion-proof performance.
2. Specifications

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2.1 Basic performance
Range: Measured range in mH2O: 0~2mH2O....200mH2O
Measured range in Bar: 0~0.2bar... .350bar
Pressure type: Gauge pressure-G; Absolute pressure-A; Sealed gauge
pressure -S.
Accuracy (based on standardand test reference conditions,including
linearity, hysteresis, repeatability)
1%FS (0~2mH2O≤range<3.5mH2O,0~0.2bar≤range<0.35bar).
0.5%FS (3.5mH2O≤range≤200mH2O,0.35bar≤range≤350bar).
0.25%FS (range ≥10mH2O, range ≥1bar).
CompensatedTemperature -10℃~60℃
Long-term stability: 0.2%FS/year.
Overload: 2 times full scale pressure
Vibration: 20g, 20Hz~2000Hz
Shock: 20g, 11ms
Protection rating: IP68.
OperationTemperature:
MPM426WPC level transmitter: -30 ≤Ta≤80 (PFA)
MPM426WPF level transmitter: -20 ≤Ta≤80 (PUR) / -10 ≤Ta≤70
(PVC/PE)
Storage Temperature:
MPM426WPC level transmitter: -40 ~85 (PFA)
MPM426WPF level transmitter: -30 ~85 (PUR) / -20 ~85
(PVC/PE)
The corresponding relationship between pressure type andrange is
shown in Table 1 below:

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Table 1
Pressure type G A S
Measured
Range in mH20
（0，3.5mH2O）√××
[3.5mH2O,200mH2O] √√×
Measured
Range in bar
(0, 35kPa) √××
[35kPa,35bar] √√×
(35bar, 350bar] ×√√
2.2 Outputparameters
Table 2
Output Signal Output form Supply Voltage
4 mA～20mADC(E) 2-wire 12V～28V DC
0～5V DC(F)
3-wire
15V～28V DC
1V～5V DC(J) 15V～28V DC
0～10V DC(V) 15V～28V DC
0.5V～4.5V DC (K2) 15V～28V DC
0.5V～4.5V DC (K3) 5V～10V DC
0.5V～2.5V DC (W) 3.2V～5V DC
RS485 MODBUS ASC II
(R4) 4-wire 3.6 V～28V DC
RS485 MODBUS_RTU (R8) 3.6 V～28V DC

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Current OutputType Parameters:
Load capacity: ≤(U-12)/0.02 (Ω).
Voltage Output Type Parameters:
Load capacity: ≥10K.
RS485 Output Type Parameters:
Baud rate: 1200, 2400, 4800, 9600 optional.
Load capacity: RS485 BUS can cascade up to 99 transmitters.
2.3 intrinsic safety parameters
Intrinsically Safe Explosion-proof Markings:
ATEX: 2460 Ⅱ1G Ex ia ⅡCT4 Ga
IECEx: CSAE 22.0019
CSANe: 22ATEX1004
CSAUS: CSA22CA801063
Class Ⅰ, Division 1, Groups A, B, C and D, T4 Ex ia ⅡCT4 Ga;
Class Ⅰ, Zone 0, AEx ia ⅡCT4 Ga ,
Intrinsically Safe Parameters Table 3:
Table 3
Power
supply
parameters
Ui Ii Li Ci Pi
Current
Output Circuit
28V
DC
100mA
DC 1.44uH
0μF 0.7 W
Voltage Output
Circuit
(15~28V
DC )Power
Supply)
28V
DC
150mA
DC 1.44uH
66nF 0.9W

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Voltage
Output Circuit
(5~10V DC
Power Supply)
10V
DC
200mA
DC 1.44uH
0.428μF 0.56W
Voltage
Output Circuit
(3.2~5V DC
Power Supply)
6V
DC
100mA
DC 1.44uH
0.318μF 0.2W
Digital
Output Circuit
(RS485)
25.4
V DC
90mA
DC 1.44uH
13.2μF 0.56W
3. Outline Construction and Installation
3.1The outline drawing is shown in Figure 1:
Unit: mm
Stainless Steel/POM End Cap（LD1/LD2）
Magnetic End Cap（LD3）

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NPT1/4 MaleThread（C6）
Figure 1
3.2Installation
3.2.1Please be surebefore Installation:
a) The measuringpressure is in the measurement range.
b) The measuringmedium is compatible with construction material.
c) The measuringmedium would not jam the pressure-leadinghole.
3.2.2 Installation method
Generally,thetransmitter should be installedperpendicular to the
horizontal direction. Ifrestricted by environmental conditions, the
transmitter is allowed to be installedat amaximum angle of30 degrees
from the horizontal direction.
Note: It is strictly forbidden to poke the pressure hole with hard objects like iron wire

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and steel needle, and it is also not allowed to press the diaphragmwith hands,
so as not to damage the diaphragm or cause the diaphragm to deform.
3.2.2.1 Installation in still water:
a) The installationmethod in the poolis shown in Figure 2. Inorder to
prevent the impact of the pump from shaking and damagingthe
transmitter,the transmitter shouldbe placedaway from the liquid
inlet and outlet.Otherwise, the steel pipe protection methodshown
in Figure 3 should be used.
b) The installationin the deep well is shownin Figure 3. Generally,the
method of inserting steel pipesis used. Itisrequired that the steel
pipecannot bebent, andthe inner diameter must be larger than the
outer diameter of the transmitter.Several small holes arepunchedat
different heightsof the steel pipeto facilitatethe smooth entry of
water into thepipe. If necessary,windasteel wire aroundthe
transmitter andlift it up and down with the steel wireto avoid
breaking the cable.
Figure 2 Figure 3

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3.2.2.2 Installation in moving water:
a) Static water devices must be installed in moving water (suchas river
courses, reservoir areas, etc.), and the sensingsurfacemust be
parallelto the direction of water flow.Toinsert steel pipes in the
water channel,the steelpipewallis requiredto beslightlythicker,
and a number of small holes are punched inthe pipe wall at different
heights to dampen water waves and eliminate theinfluence of
hydrodynamic pressure; (see Figure 4)
b) If it is asand-gravel water bedin aclear waterarea, shallow burial is
better; (see Figure 5)
c) If the flow pressure is high or there is sediment in thewater,see
Figure 6.
ConnectionBox
FlowDirection
Connection Box
Figure 4 Figure 5

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Damper
AirPocket
Figure 6
4. Electrical Connection
Table 4
4.1 Typical electrical connection
a) 2-wire:
Wire Color 2-wire(current) 3-wire(voltage) 4-wire(RS485)
Red +V +V +V
White Null +OUT RS485B
Black OV/+OUT GND GND
Yellow/Green Null Null RS485A

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Figure 7
b) 3-wire:
Figure 8
4.2 Installation Precautions
There is avented tube inthe dedicatedcableof the transmitter,which is
used to connect the back pressure chamber of the gauge pressure
sensor with theatmosphere. During installation and use, the tubemust
be connected to the atmosphere, do not be blocked, and liquids must not
flow in from thetube, otherwise the transmitter will be damaged.
5. Unpacking, Shipment Enclosed and Storage
5.1 Attentions before unpacking:
a) Be sure the package is completed, and the package shouldbe put
as the sign “UP”.
+
+
-
-
P
U
U
U
0/1～5V
P
Inpu
t
+V
GND
+OU
T
P/U Transmitter
DC current

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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 Shipment Enclosed
The transmittershould be enclosed when out of factory
MPM426W Series Level Transmitter 1pc
Cable (assembled with transmitter) Based on order
Production Manual1pc
Production Qualification Certificate 1pc
7.3 Storage
The transmitter should bestored indryventilate room, ambient
temperature-20 ~85 andthe relative humidity≤85%, no corrosive
substance in the room.
6. Operation, maintenance and troubleshooting
6.1 Operation
After the transmitter is installed accordingtothe instructions, it can be put
into operation.
Before puttingit into operation, please strictly check whether the
installation and electrical connection are correct.
Turn on the power and put it into operation.
The transmittercan work when it is connected to the power supply, but

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the output signal after 30 minutes of warm-upis more stableand reliable.
6.2 Maintenance
Please pay attention to the following points for daily maintenance:
a) Frequently check whether the electrical connection is reliable.
b) Do not poke thepressureholewith ametal wire or other hard objects
to poke the diaphragm.
6.3 Troubleshooting
If the transmitter has not output, the outputis too small or too large, the
output is unstable and other faults, the powersupply should be turned off
first, check againwhetherthe installation and wiringmeet the
requirements of the manual, whether the power supply current is correct,
and whether the vent pipe is unblocked.
If it still cannot be ruled out, the transmittermay be damaged, please
consult our company.
7. Responsibility
Within oneyearfrom the delivery date, we shall replace the instrument
with any quality fault caused by material parts or our manufacturing
techniquefree of charge. For non-qualitymalfunctionduring user’s
operation, we are in charge of repair.Butthe material cost and the
shuttle transportation fees should be borne by users.