Datasheet

MS5837-30BA
Ultra-small, gel-filled pressure sensor with stainless steel cap
TE CONNECTIVITY SENSORS /// MS5837-30BA REV C2 12/2019
Page 11
PRESSURE AND TEMPERATURE CALCULATION
Figure 9: Flow chart for pressure and temperature reading and software compensation.
Size
[1]
[bit]
min
max
C1
Pressure sensitivity | SENS
T1
unsigned int 16
16
0
65535
34982
C2
Pressure offset | OFF
T1
unsigned int 16
16
0
65535
36352
C3
Temperature coefficient of pressure sensitivity | TCS
unsigned int 16
16
0
65535
20328
C4
Temperature coefficient of pressure offset | TCO
unsigned int 16
16
0
65535
22354
C5
Reference temperature | T
REF
unsigned int 16
16
0
65535
26646
C6
Temperature coefficient of the temperature | TEMPSENS
unsigned int 16
16
0
65535
26146
D1
Digital pressure value
unsigned int 32
24
0
16777215
4958179
D2
Digital temperature value
unsigned int 32
24
0
16777215
6815414
dT
Difference between actual and reference temperature
dT
= D2 - T
REF
=
D2
-
C5 * 2
8
signed int 32
25
-16776960
16777215
-5962
1981
= 19.81 °C
OFF
Offset at actual temperature
OFF
=
OFF
T1
+
TCO
*
dT =
C2
*
2
16
+
(C4
*
dT
)
/
2
7
signed int 64
41
-17179344900
25769410560
2381326464
SENS
Sensitivity at actual temperature
SENS
=
SENS
T1
+
TCS
*
dT
=
C1 * 2
15
+
(
C3
*
dT
)
/
2
8
signed int 64
41
-8589672450
12884705280
1145816755
39998
= 3999.8 mbar
Notes
[1]
Maximal size of intermediate result during evaluation of variable
300000
0
58
P
Recommended
variable type
Description | Equation
signed int 32
Actual temperature (-40…85°C with 0.01°C resolution)
TEMP = 20°C+dT*TEMPSENS = 2000+dT *C6 /2
23
Read digital pressure and temperature data
signed int 32
Temperature compensated pressure (0…30 bar with
0.25mbar resolution)
P
= D1 * SENS - OFF =
(D1 * SENS / 2
21
- OFF) / 2
13
Convert calibration data into coefficients (see bit pattern of W1 to W4)
Variable
Example /
Typical
Value
Calculate temperature compensated pressure
8500
-4000
TEMP
41
Start
Maximum values for calculation results:
P
MIN
= 0 bar P
MAX
= 30 bar
T
MIN
= -20°C T
MAX
= 85°C T
REF
= 20°C
Read calibration data (factory calibrated) from PROM
Read digital pressure and temperature data
Calculate temperature
Calculate temperature compensated pressure
Display pressure and temperature value