1.8k Thermistor Compatibility with Xenta Controllers

[Product_Support]

Issue

Certain Xenta controllers and I/O modules are compatible with 1.8k thermistor temperature inputs. Users often seek clarification on which models support this and the specific temperature vs. resistance characteristics.

Product Line

TAC Vista

Environment

• Xenta 122-FC
• Xenta 122-HP
• Xenta 121-FC
• Xenta 121-HP
• Xenta 200
• Xenta 300
• Xenta 420A
• Xenta 450A

Cause

Users need to understand the temperature vs. resistance curve for the 1.8k thermistors used in Xenta controllers, especially for the Xenta 300 series.

Resolution

All Xenta controllers and I/O modules except the Xenta 102-AX use the same 1.8k thermistor type: 1.8KA1.

Below is a summarized Temperature vs. Resistance table for the 1.8KA1 thermistor:

Temp (°C)	Minimum kΩ	Nominal kΩ	Maximum kΩ
-50.0	60.87	63.88	67.03
-45.0	45.41	47.5	49.68
-40.0	34.23	35.68	37.2
-35.0	26.04	27.07	28.13
-30.0	19.99	20.72	21.47
-25.0	15.48	16.0	16.54
-20.0	12.09	12.46	12.84
-15.0	9.512	9.779	10.05
-10.0	7.541	7.733	7.929
-5.0	6.021	6.16	6.301
0.0	4.84	4.94	5.042
5.0	3.916	3.988	4.061
10.0	3.189	3.24	3.293
15.0	2.612	2.649	2.686
20.0	2.151	2.177	2.209
25.0	1.782	1.8	1.818
30.0	1.478	1.496	1.514
35.0	1.233	1.25	1.267
40.0	1.033	1.049	1.065
45.0	0.8698	0.8848	0.9001
50.0	0.7357	0.7497	0.7639
55.0	0.6251	0.638	0.6511
60.0	0.5334	0.5453	0.5573
65.0	0.457	0.4679	0.479
70.0	0.3931	0.4031	0.4132
75.0	0.3395	0.3485	0.3578
80.0	0.2942	0.3025	0.311
85.0	0.2559	0.2634	0.2712
90.0	0.2233	0.2302	0.2373
95.0	0.1956	0.2019	0.2083
100.0	0.1718	0.1775	0.1835
105.0	0.1514	0.1566	0.1621
110.0	0.1338	0.1386	0.1436
115.0	0.1186	0.123	0.1276
120.0	0.1054	0.1095	0.1136
125.0	0.094	0.0977	0.1015
130.0	0.084	0.0874	0.0909
135.0	0.0753	0.0784	0.0816
140.0	0.0676	0.0705	0.0735
145.0	0.0609	0.0635	0.0663
150.0	0.0549	0.0574	0.0599