Pt200 | GUILCOR SENSORS

Pt200
Temperature sensors

Pt200 temperature sensors offer improved signal resolution while maintaining the precision and reliability of platinum RTDs.

Maximum precision
+/- 0.10°K

Minimum temperature
-200°C

Maximum temperature
+850°C

Minimum dimensions
2 x 8 x30

Response time
Medium

Self-heating
Low

Price
High

Drift
Low

What is a Pt200 sensor ?

The Pt200 is a pure platinum resistance probe (99.99%), with a nominal resistance of 200 Ω at 0 °C.

It is an evolution of the Pt100, providing a voltage output that is twice as high, which improves measurement resolution and noise rejection without altering thermal behavior.

The Pt200 is therefore ideal for precision industrial applications and long-distance wiring embedded systems.

Operating principle

Like all platinum RTD sensors, the Pt200 follows the Callendar–Van Dusen equation:

R(T) = R0[(1+A⋅T+B⋅T²+C⋅(T-100)⋅T³]

With :

R₀ = 200 Ω (pour Pt200)
A = 3,9083 × 10⁻³
B = -5,775 × 10⁻⁷
C = −4,183×10−12 (pour T < 0 °C)

Technical specifications

Parameter	Typical Value
Nominal resistance at 0 °C	200 Ω
Temperature coefficient (α)	0,00385 °C⁻¹
Measurement range	−200 °C to +850 °C
Linearity	Excellent
Element material	Platinium pur
Typical measuring current	0,1 → 1 mA
Response time	0,5 s (gain Ø3 mm)
Long-term drift	< 0,05 °C/year

Wiring configuration

Type	Description	Precision
2-wire	Simple but the influence of cables is not negligible.	⚠️ Average
3-wire	Partial compensation for line losses.	✅ Good
4-wire	Kelvin measurement eliminates the resistance of conductors.	🏆 Excellent

Self-heating

The Pt200 generates a higher voltage for the same current, allowing for a lower excitation (≈ 0.3 mA).

Result: a self-heating of less than 0.03 °C, perfect for precise long-term applications.

Application areas

⚙️ High-precision industrial instrumentation

🧪 Test benches and automatic calibrations

🚀 Embedded systems and aerospace control

🧠 Long-distance scientific measurement equipment

🔧 High-end replacement for Pt100 in noisy environments

Should I choose a Pt200 sensor ?

Strengths points

🔍 Naturally amplified signal
→ With 200 Ω at 0 °C, the Pt200 generates a voltage twice as high as a Pt100 → better resolution without amplifying as much.
🧠 Excellent noise immunity
→ Its greater resistance allows for better rejection of electromagnetic interference, ideal for long distances.
🧩 Compatible Pt100
→ Same equation, same coefficient α = 0.00385: it can replace a Pt100 in most systems without recalibration.

Weaknesses points

💸 Less common sensor
→ More platinum = higher price, especially on miniaturized sensors or stainless steel sheathed ones.
⚡ Excitation current to adjust
→ A voltage that is too high can saturate the amplifiers; therefore, the supply current must be reduced (< 0.5 mA).
🧯 Rarely used in the market
→ Less common than the Pt100, which limits the availability of compatible converters and controllers.

Useful information

Here is some useful information regarding Pt200 sensors.

Table of ohmic values

Temp (°C)	0	1	2	3	4	5	6	7	8	9
0	200,00	200,78	201,56	202,34	203,12	203,91	204,69	205,47	206,25	207,03
10	207,81	208,58	209,36	210,14	210,92	211,70	212,48	213,25	214,03	214,81
20	215,59	216,36	217,14	217,92	218,69	219,47	220,25	221,02	221,80	222,57
30	223,35	224,12	224,89	225,67	226,44	227,22	227,99	228,76	229,54	230,31
40	231,08	231,85	232,63	233,40	234,17	234,94	235,71	236,48	237,25	238,02
50	238,79	239,56	240,33	241,10	241,87	242,64	243,41	244,18	244,95	245,72
60	246,48	247,25	248,02	248,79	249,55	250,32	251,09	251,85	252,62	253,38
70	254,15	254,92	255,68	256,45	257,21	257,97	258,74	259,50	260,27	261,03
80	261,79	262,56	263,32	264,08	264,84	265,61	266,37	267,13	267,89	268,65
90	269,41	270,17	270,94	271,70	272,46	273,22	273,97	274,73	275,49	276,25
100	277,01	277,77	278,53	279,29	280,04	280,80	281,56	282,32	283,07	283,83
110	284,59	285,34	286,10	286,85	287,61	288,36	289,12	289,87	290,63	291,38
120	292,14	292,89	293,64	294,40	295,15	295,90	296,66	297,41	298,16	298,91
130	299,66	300,42	301,17	301,92	302,67	303,42	304,17	304,92	305,67	306,42
140	307,17	307,92	308,67	309,42	310,16	310,91	311,66	312,41	313,16	313,90
150	314,65	315,40	316,14	316,89	317,64	318,38	319,13	319,87	320,62	321,36
160	322,11	322,85	323,60	324,34	325,09	325,83	326,57	327,32	328,06	328,80
170	329,54	330,29	331,03	331,77	332,51	333,25	333,99	334,74	335,48	336,22
180	336,96	337,70	338,44	339,18	339,92	340,65	341,39	342,13	342,87	343,61
190	344,35	345,08	345,82	346,56	347,30	348,03	348,77	349,50	350,24	350,98
200	351,71	352,45	353,18	353,92	354,65	355,39	356,12	356,85	357,59	358,32
210	359,06	359,79	360,52	361,25	361,99	362,72	363,45	364,18	364,91	365,64
220	366,38	367,11	367,84	368,57	369,30	370,03	370,76	371,49	372,21	372,94
230	373,67	374,40	375,13	375,86	376,58	377,31	378,04	378,77	379,49	380,22
240	380,95	381,67	382,40	383,12	383,85	384,57	385,30	386,02	386,75	387,47
250	388,20	388,92	389,64	390,37	391,09	391,81	392,54	393,26	393,98	394,70
260	395,42	396,15	396,87	397,59	398,31	399,03	399,75	400,47	401,19	401,91
270	402,63	403,35	404,07	404,79	405,50	406,22	406,94	407,66	408,38	409,09
280	409,81	410,53	411,24	411,96	412,68	413,39	414,11	414,82	415,54	416,25
290	416,97	417,68	418,40	419,11	419,82	420,54	421,25	421,96	422,68	423,39
300	424,10	424,82	425,53	426,24	426,95	427,66	428,37	429,08	429,79	430,50
310	431,22	431,93	432,63	433,34	434,05	434,76	435,47	436,18	436,89	437,60
320	438,30	439,01	439,72	440,43	441,13	441,84	442,55	443,25	443,96	444,66
330	445,37	446,08	446,78	447,49	448,19	448,89	449,60	450,30	451,01	451,71
340	452,41	453,12	453,82	454,52	455,22	455,93	456,63	457,33	458,03	458,73
350	459,43	460,13	460,83	461,53	462,23	462,93	463,63	464,33	465,03	465,73
360	466,43	467,13	467,83	468,52	469,22	469,92	470,62	471,31	472,01	472,71
370	473,40	474,10	474,79	475,49	476,19	476,88	477,58	478,27	478,96	479,66
380	480,35	481,05	481,74	482,43	483,13	483,82	484,51	485,20	485,90	486,59
390	487,28	487,97	488,66	489,35	490,04	490,73	491,43	492,12	492,81	493,49
400	494,18	494,87	495,56	496,25	496,94	497,63	498,32	499,00	499,69	500,38

Precision class table

Temperature (°C)	Classe A	Classe B	Classe 1/3 B (DIN)	Classe 1/10 B (DIN)
-200	0,55	1,3	0,4333	0,13
-190	0,53	1,25	0,4167	0,125
-180	0,51	1,2	0,4	0,12
-170	0,49	1,15	0,3833	0,115
-160	0,47	1,1	0,3667	0,11
-150	0,45	1,05	0,35	0,105
-140	0,43	1	0,3333	0,1
-130	0,41	0,95	0,3167	0,095
-120	0,39	0,9	0,3	0,09
-110	0,37	0,85	0,2833	0,085
-100	0,35	0,8	0,2667	0,08
-90	0,33	0,75	0,25	0,075
-80	0,31	0,7	0,2333	0,07
-70	0,29	0,65	0,2167	0,065
-60	0,27	0,6	0,2	0,06
-50	0,25	0,55	0,1833	0,055
-40	0,23	0,5	0,1667	0,05
-30	0,21	0,45	0,15	0,045
-20	0,19	0,4	0,1333	0,04
-10	0,17	0,35	0,1167	0,035
0	0,15	0,3	0,1	0,03
10	0,17	0,35	0,1167	0,035
20	0,19	0,4	0,1333	0,04
30	0,21	0,45	0,15	0,045
40	0,23	0,5	0,1667	0,05
50	0,25	0,55	0,1833	0,055
60	0,27	0,6	0,2	0,06
70	0,29	0,65	0,2167	0,065
80	0,31	0,7	0,2333	0,07
90	0,33	0,75	0,25	0,075
100	0,35	0,8	0,2667	0,08
110	0,37	0,85	0,2833	0,085
120	0,39	0,9	0,3	0,09
130	0,41	0,95	0,3167	0,095
140	0,43	1	0,3333	0,1
150	0,45	1,05	0,35	0,105
160	0,47	1,1	0,3667	0,11
170	0,49	1,15	0,3833	0,115
180	0,51	1,2	0,4	0,12
190	0,53	1,25	0,4167	0,125
200	0,55	1,3	0,4333	0,13

Example of application of the linearization equation of a PT200

The Pt200 follows the normalized Callendar–Van Dusen equation, identical to that of the Pt100, but with a doubled nominal resistance.

R(T) = R₀ [1 + A·T + B·T² + C·(T − 100)·T³]

with :

R₀ = 200 Ω
A = 3,9083 × 10⁻³
B = −5,775 × 10⁻⁷
C = −4,183 × 10⁻¹² (pour T < 0 °C)

This equation provides a stable, linear, and reproducible relationship from −200 °C to +850 °C.

🔹 Example 1 : calculation of resistance at 100 °C

R(100) = 200 × [1 + 3,9083 × 10⁻³ × 100 − 5,775 × 10⁻⁷ × 100²]

R(100) = 200 × (1 + 0,39083 − 0,005775)

R(100) = 200 × 1,385055 = 277,01 Ω

✅ Result : at 100 °C, the resistance of a Pt200 is approximately 277.0 Ω.

🔹 Example 2 : calculating the temperature from a measured resistance

A resistance R=236.2 Ω is measured.

What is the corresponding temperature?

T = (−A + √(A² − 4B(1 − R/R₀))) / (2B)

T = (−3,9083 × 10⁻³ + √[(3,9083 × 10⁻³)² − 4 × (−5,775 × 10⁻⁷) × (1 − 236,2 / 200)]) / [2 × (−5,775 × 10⁻⁷)]

T ≈ 47 °C

✅ Result : the equivalent temperature is approximately 47 °C.

🔹 Technical notes

The Pt200 provides a voltage that is twice that of the Pt100 for the same current → better ADC resolution.
The equation can be directly integrated into a microcontroller firmware (Arduino, STM32, ESP32, etc.).
Below 0 °C, the cubic component C(T−100)T3 becomes essential to maintain the accuracy of ±0.1 °C.

Integration diagram in an electronic system

The Pt200 generates a proportionally higher signal than the Pt100, which allows for reduced excitation current and limits self-heating.

It is perfectly suited for 3 or 4 wire differential configurations.

🔹 Typical components of the configuration

Component	Function
RTD Pt200 (3 or 4 wires)	Sensitive element in pure platinum
Stable current source (~0.3 mA)	Provides a constant current
Instrumentation amplifier (INA333, AD8421)	Amplify the tension from the sensor
High-resolution ADC (≥ 16 bits)	Digitize the voltage for the microcontroller
Microcontroller (STM32, ESP32, Arduino)	Calculate the temperature using Callendar–Van Dusen
Shielded wiring	Reduces electromagnetic noise over long distances

🔹 Functional diagram (ASCII)

              +3.3 V / +5 V
                   │
       Power source (0.3 mA)
                   │
                [ Pt200 ]
       (2 power wires + 2 measurement wires)
           │                   │
           │                   │
  Diff. amplifier ───→ High-resolution ADC
                              │
                       [ Microcontroller ]
                  (Calcul T = f(R) + compensation)

🔹 Operating Principle

1️⃣ The constant current flows through the Pt200.

→ At 0 °C: V = 200 Ω × 0.3 mA = 60 mV

→ At 100 °C: V = 277 Ω × 0.3 mA = 83 mV

2️⃣ The differential amplifier boosts the signal (gain ≈ 50 to 100).

→ Typical output: 3 to 8 V depending on the ADC configuration.

3️⃣ The microcontroller calculates the temperature using the Callendar–Van Dusen equation.

🔹 Best Practices