NTC THERMISTORS: TYPE MA
Crown Industrial Estate, Priorswood Road 808 US Highway 1 967 Windfall Road
Taunton, Somerset TA2 8QY UK Edison, New Jersey 08817-4695 USA St. Marys, Pennsylvania 15857-3397 USA
Tel +44 (0) 1823 335200 Tel +1 (732) 287 2870 Tel +1 (814) 834 9140
Fax +44 (0) 1823 332637 Fax +1 (732) 287 8847 Fax +1 (814) 781 7969
DESCRIPTION:
Our Biomedical Chip Thermistor assemblies are
designed for use in applications involving both
intermittent and continuous patient temperature
monitoring. Repeatability and fast response are es-
sential not only for the intermittent temperature
requirements associated with oral and rectal fever
measurements, but also with the continuous moni-
toring 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 monitor-
ing for skin surface, tympanic, esophageal, foley
catheters and biofeedback applications has also
improved due to the high stability and tight inter-
changeable tolerances designed into each Thermo-
metrics’ Biomedical assembly.
APPLICATIONS:
A complete line of standard sub-assemblies is avail-
able, as shown in Figure 1; however, continuous
research and development efforts within Thermo-
metrics 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 0° C to 50°
C. Although low in cost, these highly stable, preci-
sion thermochips provide the reliability, tight inter-
changeable tolerances, geometries, and fast
response times required. To keep pace with this
ever-improving biomedical market, our material sys-
tem and processing parameters are closely moni-
tored and improved to continually provide you with
reliable, quality products. In addition, should you
require it, Thermometrics employs a complete staff
of experienced full-time applications engineers who
welcome your inquiries, whether it’s for assistance,
or to help with your design requirements concerning
new and existing applications.
g
TYPE MA
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 stainless 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 ohms at 25° C are
available.
Refer to Table 1 for typical design parameters.
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 thermome-
ters in use today. It features rugged construction with tip sensitive shaft assemblies exhibit-
ing resistance values of 2252, 3000, 5000, and 10,000 ohms at 25° C.
Refer to Table 1 for typical design parameters.
Designed for use in catheter assemblies these sensors are available with nominal resistance
values of 2252, 3000, 5000, and 10,000 ohms at 25° C. Close monitoring of manufactur-
ing processes allow us to maintain tight interchangeability tolerances with volume production.
Typical design parameters are represented in Table 1.
NOTE: .030"(10K ohm only) and .050" diameters available with kapton sleeve only.
.070" diameter normally supplied with molded plastic tip.
TABLE 1 Assembly Type MA100 MA200 MA300
Standard .030" .050" .070" .156" .375"
Diameters D .080"
Body Length L 3/8" 3.75" N / A
Lead Length A 24" 2" 24"
Tolerance See Table See Table See Table
Wire Gauge 28, 30, 32, 38 AWG 30 AWG 30 AWG
Standard Wire *Heavy Isomid
Insulation *Medical Grade PVC Teflon Medical Grade PVC
*Polyurethane with Teflon
Nylon Overcoat
Body Material Molded Plastic or Lexan Shaft Stainless
Kapton Sleeve Aluminum Tip Steel
Nominal R Values 2252, 3000, 5000, 10,000
@ 25°C Ohms
DATA:
Our biomedical series thermistor chips and sub
assemblies are designed to be interchangeable
over a 0°C to 50°C range. Best overall stability is
maintained when exposure and storage tempera-
tures remain below 70°C.
CODING:
MA XXXXX - XXX - X
TOLERANCE CODE:
REFER TO TABLE
RESISTANCE CODE:*
232 = 2,252 OHMS
302 = 3,000 OHMS
502 = 5,000 OHMS
103 = 10,000 OHMS
103(Y) = 10,000 OHMS
*Refer to Resistance vs. Temperature Table
STANDARD ASSEMBLIES
100FA - Series 100, .070" diameter molded
plastic tip, 30 gauge PVC insulated
ribbon cable.
100FD - Series 100, .070" diameter molded
plastic tip, 32 gauge bifilar heavy
isomid insulation.
100DD - Series 100, .050" diameter kapton
sleeve with 32 gauge bifilar heavy
isomid insulation.
100BF - Series 100, .030" diameter kapton
sleeve with 38 gauge bifilar heavy
isomid insulation.
200LC - Series 200, .156" diameter aluminum
tip, 30 gauge teflon leads.
300TA - Series 300, .375" diameter stainless
steel cup, 30 gauge PVC insulated
ribbon cable.
300TB - Series 300, .375" diameter stainless
steel cup, 30 gauge teflon insulated
ribbon cable.
100GG - Series, 100, .080” diameter molded
plastic tip, 28 gauge kynar insulated
twisted pair.
* Response time provided is for assembly plunged
from 25°C air to 5°C still water
TOLERANCE CODE AND TEMPERATURE RANGE
TEMP 2252 3k 5k 10k 103(Y)
°C OHMS OHMS OHMS OHMS OHMS
0 7352.90 9795.16 16325.3 32650.5 29491.24
1 6988.42 9309.62 15516.0 31032.1 28157.49
2 6643.38 8849.98 14750.0 29499.9 26891.19
3 6317.41 8415.73 14026.2 28052.4 25688.61
4 6009.39 8005.39 13342.3 26684.6 24546.22
5 5718.10 7617.37 12695.6 25391.2 23460.72
6 5442.68 7250.46 12084.1 24168.2 22428.99
7 5182.12 6903.35 11505.6 23011.2 21448.12
8 4935.54 6574.88 10958.1 21916.3 20515.34
9 4702.12 6263.93 10439.9 20879.8 19628.07
10 4481.09 5969.48 9949.14 19898.3 18783.87
11 4271.72 5690.57 9484.28 18968.6 17980.43
12 4073.33 5426.28 9043.80 18087.6 17215.58
13 3885.28 5175.78 8626.30 17252.6 16487.30
14 3706.99 4938.27 8230.45 16460.9 15793.65
15 3537.90 4713.01 7855.01 15710.0 15132.82
16 3377.47 4499.30 7498.83 14997.7 14503.11
17 3225.23 4296.48 7160.80 14321.6 13902.89
18 3080.70 4103.95 6839.92 13679.8 13330.64
19 2943.46 3921.13 6535.22 13070.4 12784.92
20 2813.11 3747.48 6245.80 12491.6 12264.39
21 2689.26 3582.49 5970.82 11941.6 11767.75
22 2571.54 3425.68 5709.47 11418.9 11293.80
23 2459.64 6276.61 5461.01 10922.0 10841.39
24 2353.22 3134.84 5224.74 10449.5 10409.44
25 2252.00 3000.00 5000.00 10000.0 10000.00
26 2155.69 2871.70 4786.16 9572.32 9602.89
27 2064.02 2749.59 4582.64 9165.29 9226.41
28 1976.76 2633.34 4388.89 8777.79 8866.62
29 1893.67 2522.10 4204.34 8408.68 8522.70
30 1814.51 2417.19 4028.66 8057.31 8193.89
31 1739.09 2316.73 3861.22 7722.43 7879.43
32 1667.22 2220.99 3701.65 7403.29 7578.65
33 1598.51 2129.52 3549.20 7098.42 7290.88
34 1533.20 2042.50 3404.18 6808.36 7015.50
35 1470.89 1959.39 3265.65 6531.31 6751.92
36 1411.58 1880.47 3134.12 6265.75 6499.57
37 1354.91 1804.94 3008.23 6016.47 6257.93
38 1300.77 1732.82 2888.03 5776.05 6026.49
39 1249.08 1663.96 2773.26 5546.53 5804.78
40 1199.72 1598.20 2663.67 5327.34 5592.33
41 1152.57 1535.39 2558.99 5117.97 5388.73
42 1107.52 1475.38 2458.97 4917.94 5193.56
43 1064.47 1418.03 2363.39 4726.77 5006.43
44 1023.30 1363.17 2271.95 4543.91 4826.98
45 983.97 1310.80 2184.66 4369.33 4654.86
46 946.02 1260.25 2100.92 4200.84 4489.73
47 909.99 1212.24 2020.40 4040.81 5331.28
48 875.92 1166.85 1944.76 3889.51 4179.20
49 842.96 1122.95 1871.59 3743.17 4033.22
50 811.42 1080.93 1801.55 3603.10 3893.05
THERMAL RESPONSE TIME (63% RESPONSE) RESISTANCE VS. TEMPERATURE
Series Still Air Still Water*
MA100
Catheter Assembly 15 sec. 2.0 sec.
MA200
Oral-Rectal Assembly 35 sec. 0.6 sec.
MA300
Skin Surface Assembly 45 sec. 2.0 sec.
Tolerance Code
Temperature
Range ABC
°C ± °C ±°C ±°C
0-20 .15 .2 .25
20-35 .1 .15 .2
35-39 .05 .1 .15
39-42 .075 .15 .2
42-45 .1 .15 .2
45-50 .15 .2 .25
