Biomedical Chip
Thermistors
NTC Type MA
Applications
A complete line of standard sub-assemblies is available.
Continuous research and development efforts within
Thermometrics have resulted not only in these field
proven designs, but in the development of our Unitherm
Thermochip Thermistor, designed exclusively for
biomedical applications in the range of 32°F to 122°F
(0°C to 50°C) .
Although low in cost , these highly stable,
precision thermochips provide the reliability, tight
interchangeable tolerances, geometries, and fast
response times that are often required. Thermometrics
employs experienced applications engineers who
welcome inquiries, whether for assistance, or to help
with your design requirements concerning new and
existing applications.
Our Biomedical Chip Thermistor assemblies are
designed for use in applications involving both
intermittent and continuous patient temperature
monitoring. Repeatability and fast response are
essential not only for the intermittent temperature
requirements associated with oral and rectal fever
measurements, but also with the continuous monitoring
often necessary during induced-hypothermia and
general anesthesia, or when employed in the care of
infants and premature babies. Intensive care units
along with recovery rooms have also adopted patient
temperature as part of their vital sign monitoring
procedures. Temperature monitoring for skin surface,
tympanic, esophageal, foley catheters and biofeedback
applications has also improved due to the high stability
and tight interchangeable tolerances designed into
each Thermometrics’ Biomedical assembly.
Amphenol
Advanced Sensors
NTC Type MA Specifications
MA100
Designed for use in catheter assemblies, these sensors
are available with nominal resistance values of 2252,
3000, 5000, and 10,000 Ω at 77°F (25°C). Close monitor-
ing of manufacturing processes allow Thermometrics
to maintain tight interchangeability tolerances with
volume production. Typical design parameters are rep-
resented in Assembly Type table.
0.030 in (0.76 mm) (10 KΩ only) and 0.050 in(1.27mm)
diameters available with kapton sleeve only.
0.070 in (1.78 mm) diameter normally supplied with
molded plastic tip.
MA200
Intermittent body temperature measurements are
common practice in all phases of patient care. This
assembly is ideally suited for the disposable cover oral
and rectal fever thermometers in use today. It features
rugged construction with tip sensitive shaft assemblies
exhibiting resistance values of 2252, 3000, 5000, and
10,000 Ω at 77°F (25°C). Refer to Assembly Type table
for typical design parameters.
MA300
Routine continuous patient temperature monitoring is
now feasible by using the convenience of the patient’s
skin site as an indicator of body temperature. The stain-
less steel housing used is suitable for both reusable and
disposable applications, while maintaining maximum
patient comfort . Nominal resistance values of 2252,
3000, 5000, and 10,000 Ω at 77°F (25°C) are available.
Refer to Assembly Type table for typical design param-
eters.
Assembly Type
Assembly
Type MA100 MA200 MA300
Standard
Diameters
(D)
0.030 in (0.762 mm)
0.050 in (1.27 mm)
0.070 in (1.78 mm)
0.080 in (2.03 mm)
0.156 in (3.96 mm) 0.375 in (9.52 mm)
Body
Length (L)
3/8 in (9.52 mm) 3.75 in (95.25 mm) N/A
Lead Length
(A)
3/8 in (9.52 mm) 3.75 in (95.25 mm) N/A
Tolerance See Tolerance Code
and Temperature
Table
See Tolerance Code
and Temperature
Table
See Tolerance Code
and Temperature
Table
Wire Gauge 20, 30, 32, 38, AWG 30 AWG 30 AWG
Standard
Wire
Insulation
*Heavy Isomid
*Medical Grade PVC
*Polyurethane with
Nylon Overcoat
PTFE Medical Grade PVC
PTFE
Body
Material
Molded Plastic or
Kapton Sleeve
Lexan Shaft
Aluminum Tip
Stainless Steel
Nominal R Values @ 77°F (25°C) 2252 Ω, 3000 Ω, 5000 Ω, 10,000 Ω
(for all three types)
Thermal Response Time (63% Response)
Series Still Air Still Water*
MA100
Catherter Assembly
15 seconds 2.0 seconds
MA200
Oral-Rectal Assembly
35 seconds 0.6 seconds
MA300
Skin Surface Assembly
45 seconds 2.0 seconds
*Response time provided is for assembly plunged from 77°F (25°C) air to 41°F (5°C) water.
NTC Type MA Specifications
Tolerance Code and Temperature Range
Tolerance Code
Temperature
Range °F (°C)
A
±°F (±°C)
B
±°F (±°C)
C
±°F (±°C)
32 to 68 (0 to 20) 0.27 (0.15) 0.36 (0.2) 0.45 (0.25)
68 to 95 (20 to 35) 0.18 (0.1) 0.27 (0.15) 0.36 (0.2)
95 to 102 (35 to 39) 0.09 (0.05) 0.18 (0.1) 0.27 (0.15)
102 to 107.60 (39 to 42) 0.14 (0.075 0.27 (0.15) 0.36 (0.2)
107.60 to 113 (42 to 45) 0.18 (0.1) 0.27 (0.15) 0.36 (0.2)
113 to 122 (45 to 50) 0.27 (0.15) 0.36 (0.2) 0.45 (0.25)
Data
Our biomedical series thermistor chips and
sub-assemblies are designed to be interchangeable
over a 32°F to 122°F (0°C to 50°C) range. Best overall
stability is maintained when exposure and storage
temperatures remain below 158°F (70°C).
Temperature
°F (°C) 2252 Ω 3 kΩ 5 kΩ 10 kΩ 103(Y) Ω
32.00 (0) 7373.00 9821.93 16369.9 32739.8 29565.8
33.80 (1) 7005.80 9332.76 15554.6 31109.2 28224.8
35.60 (2) 6659.04 8870.84 14784.7 29569.5 26951.9
37.40 (3) 6331.49 8434.49 14057.5 28115.0 25743.3
39.20 (4) 6021.97 8022.17 13370.3 26740.6 24595.5
41.00 (5) 5729.40 7632.41 12720.7 25441.4 23505.0
42.80 (6) 5452.74 7263.87 12106.4 24212.9 22468.7
44.60 (7) 5191.06 6915.27 11525.4 23050.9 21483.8
46.40 (8) 4943.46 6585.43 10975.7 21951.4 20547.2
48.20 (9) 4709.11 6273.23 10455.4 20910.8 19656.6
50.00 (10) 4487.22 5977.64 9962.74 19925.5 18809.3
51.80 (11) 4277.07 5697.69 9496.15 18992.3 18003.1
53.60 (12) 4077.97 5432.47 9054.11 18108.2 17235.7
55.40 (13) 3889.29 5181.11 8635.19 17270.4 16505.1
57.20 (14) 3710.42 4942.83 8238.05 16476.1 15809.4
59.00 (15) 3540.80 4716.88 7861.46 15722.9 15146.7
60.80 (16) 3379.91 4502.54 7504.24 15008.5 14515.3
62.60 (17) 3227.24 4299.17 7165.28 14330.6 13913.6
64.40 (18) 3082.34 4106.14 6843.57 13687.1 13340.0
66.20 (19) 2944.77 3922.88 6538.13 13076.3 12793.0
68.00 (20) 2814.12 3748.83 6248.05 12496.1 12271.4
69.80 (21) 2690.01 3583.49 5972.48 11945.0 11773.8
71.60 (22) 2572.07 3426.38 5710.63 11421.3 11299.0
73.40 (23) 2459.96 3277.03 5461.72 10923.4 10845.8
75.20 (24) 2353.37 3135.04 5225.07 10450.1 10413.1
77.00 (25) 2252.00 3000.00 5000.00 10000.0 10000.0
78.80 (26) 2155.56 2871.53 4785.88 9571.77 9605.42
80.60 (27) 2063.79 2749.28 4582.13 9164.26 9228.45
82.40 (28) 1976.44 2632.91 4388.19 8776.38 8868.24
84.20 (29) 1893.27 2522.12 4203.54 8407.07 8523.96
86.00 (30) 1814.07 2416.61 4027.68 8055.35 8194.82
87.80 (31) 1738.61 2316.09 3860.15 7720.30 7880.09
89.60 (32) 1666.71 2220.31 3700.51 7401.03 7579.07
91.40 (33) 1598.18 2129.02 3548.36 7096.72 7291.10
93.20 (34) 1532.85 2041.98 3403.30 6806.60 7015.55
95.00 (35) 1470.54 1958.98 3264.97 6529.94 6751.83
96.80 (36) 1411.11 1879.81 3133.02 6266.03 6499.37
98.60 (37) 1354.41 1804.27 3007.12 6014.23 6257.64
100.40 (38) 1300.29 1732.18 2886.96 5773.93 6026.13
102.20 (39) 1248.63 1663.36 2772.27 5544.53 5804.36
104.00 (40) 1199.30 1597.65 2662.75 5325.50 5591.88
105.80 (41) 1152.19 1534.89 2558.15 5116.30 5388.26
107.60 (42) 1107.19 1474.94 2458.23 4916.46 5193.09
109.40 (43) 1064.18 1417.65 2362.75 4725.49 5005.96
111.20 (44) 1023.08 1362.89 2271.49 4542.98 4826.53
113.00 (45) 983.78 1310.55 2184.24 4368.49 4654.43
114.80 (46) 946.21 1260.49 2100.82 4201.64 4489.33
116.60 (47) 910.27 1212.62 2021.03 4042.05 4330.91
118.40 (48) 875.89 1166.81 1944.69 3889.38 4178.88
120.20 (49) 842.99 1122.99 1871.65 3743.29 4032.94
122.00 (50) 811.50 1081.04 1801.73 3603.46 3892.83
Resistance vs Temperature
AAS-920-321B-06/2015
www.amphenol-sensors.com
© 2015 Amphenol Corporation. All Rights Reserved. Specifications are subject to change without notice.
Other company names and product names used in this document are the registered trademarks or
trademarks of their respective owners.
Amphenol
Advanced Sensors
NTC Type MA Specifications
Ordering Information
The code number to be ordered may be specif ied as follows:
MA
Code Standard Assemblies
100FA Series 100, 0.070 in (1.78 mm) diameter molded plastic tip,
30 gauge PVC insulated ribbon cable.
100FD Series 100, 0.070 in (1.78 mm) diameter molded plastic tip,
32 gauge bifilar heavy isomid insulation.
100DD Series 100, 0.050 in (1.27 mm) diameter kapton sleeve with
32 gauge bifilar heavy isomid insulation.
100BF Series 100, 0.030 in (0.768 mm) diameter kapton sleeve with
38 gauge bifilar heavy isomid insulation.
200LC Series 200, 0.156 in (3.96 mm) diameter aluminum tip,
30 gauge PTFE leads.
300TA Series 300, 0.375 in (9.52 mm) diameter stainless steel cup,
30 gauge PVC insulated ribbon cable.
300TB Series 300, 0.375 in (9.52 mm) diameter stainless steel cup,
30 gauge PTFE insulated ribbon cable.
100GG Series 100, 0.080 in (2.03 mm) diameter molded plastic tip,
28 gauge kynar insulated twisted pair.
Code Resistance Cable*
232 2252 Ω
302 3000 Ω
502 5000 Ω
103 10,000 Ω
103 (Y) 10,000 Ω
Code Tolerance
X Refer to tolerance code and temperature
range table
MA - ______ - ______ - ______ Typical Model Number
*Refer to resistance vs temperature table on previous page.
