HQ-HQ1002 Pressure Transmitter Calibration Guide：The Path to Precision Measurement with Diffused Silicon Sensors

　　As a core diffused silicon sensor device widely used in the industrial sector，the calibration accuracy of the HQ-HQ1002 pressure transmitter is directly related to the reliability of liquid/gas pressure measurement。This article systematically explains the calibration procedures，wiring specifications，and common troubleshooting methods for models such as KYB18G07M1P4C3-I and ZWP-L61-K from a practical operation perspective，helping technicians ensure that product series such as EDYBT-4 and HB-31C maintain high-accuracy output of ±0.1%FS，while extending the service life of models such as PQ50-GB10CG12M4B under harsh operating conditions。

1、Detailed Explanation of the Core Calibration Process for Diffused Silicon Pressure Transmitters

　　Standard calibration of the HQ-HQ1002 pressure transmitter must comply with ISO 9001 quality management system requirements。First，prepare a Class 0.05 standard pressure source，a precision ammeter（resolution ≤0.01mA），and a matching calibrator（MSZ-MSZ11 dedicated instrument is recommended）。The specific steps include：

　　1. Zero calibration：Under no-load conditions，adjust the zero potentiometer using the TY-TY211 factory-supplied magnetic dialer，so that the 4-20mA output remains stable within the range of 4.000±0.008mA。For high-temperature models such as KYB11G01M1PXC1-I，preheat for 30 minutes to the operating temperature before calibration。

　　2. Full-scale calibration：Apply the rated pressure（refer to the measuring range marked on the ZWP-L61-K sensor），and adjust the span potentiometer so that the output current reaches 20.000±0.010mA。Note that the EDYBT-4 transmitter requires three cycle tests to confirm that the repeatability error is ≤0.05%。

2、Wiring Specifications and Signal Processing for Multiple Pressure Transmitter Models

　　HQ series diffused silicon sensors use the internationally common two-wire wiring method，but different models have detailed differences：

　　• KYB18G07M1P4C3-I model：The red wire connects to the 24VDC positive terminal，the black wire connects to the signal input terminal，and the shielding layer must be grounded at one end。Special attention should be paid that this model includes a dedicated lightning protection module in the MS-MS501 accessory kit。

　　• PQ50-GB10CG12M4B model：With a built-in signal isolator，an independent power supply must be additionally provided for the blue wire。It is recommended to use the HB-31C safety barrier as matching equipment，which can effectively suppress on-site electromagnetic interference。

　　Abnormal signal handling：When the output current remains below 3.8mA，first check whether the shunt resistor of the MSZ11 matching instrument is normal（nominal 250Ω），then check whether the diffused silicon diaphragm is blocked by medium crystallization。

3、Measuring Range Setting and Operating Condition Matching Tips

　　The default range of the ZWP-L61-K pressure transmitter is 0-1MPa，but adjustment is often required in practical applications：

　　1. Range compression technology：By adjusting the DIP switch on the back of the sensor，the 10MPa full scale of the EDYBT-4 model can be compressed to the actually required 6MPa，which can improve measurement accuracy to 0.075%FS。

　　2. Medium compatibility treatment：For corrosive gas measurement，it is recommended to select the TY211 original 316L stainless steel isolation diaphragm。When measuring liquids，the ceramic piezoresistive core of the HQ-HQ1002 must be installed vertically to avoid particle deposition。

　　3. Temperature compensation：The PT100 temperature sensor built into the HB-31C model can automatically compensate for thermal drift within the range of -20℃~85℃；beyond this range，an external KYB11G01M1PXC1-I temperature transmitter is required。

4、Maintenance Strategies to Extend Equipment Service Life

　　The PQ50-GB10CG12M4B pressure transmitter has an average service life of 8 years under continuous operating conditions，but the following must be observed：

　　• Periodic maintenance：Check the aging condition of the O-ring seal in the MS-MS501 accessories every 6 months，and clean the surface of the diffused silicon diaphragm with anhydrous ethanol every year。

　　• Overload protection：The ZWP-L61-K model allows short-term 150% overpressure，but the EDYBT-4 model must not exceed 110%。It is recommended to install a dedicated HQ series pressure relief valve on pump equipment。

　　• Storage specifications：When not in use for a long period，models such as HB-31C should be stored in an environment with humidity ＜60%，and the pressure port sealing cap should be kept intact。

5、Common Fault Diagnosis and Solutions

　　Case 1：Output signal fluctuation
　　Phenomenon：The output current of the KYB18G07M1P4C3-I model jumps irregularly between 18.5-19.3mA
　　Troubleshooting steps：
　　1) Use the MSZ11 instrument to detect power supply voltage fluctuation ＜0.5%
　　2) Check whether the PQ50-GB10CG12M4B wiring terminals are oxidized
　　3) Finally confirm that a gas-liquid mixed phase exists in the pressure guiding tube of the diffused silicon sensor

　　Case 2：Zero drift exceeds the standard
　　Involved model：TY-TY211 pressure transmitter
　　Solution：
　　1) Perform forced zero calibration 3 times
　　2) Replace the temperature compensation module in the MS-MS501 accessory package
　　3) If still ineffective，return to the factory for recalibration of the diffused silicon chip

Conclusion and Action Guide

　　Mastering the professional calibration methods for the HQ-HQ1002 pressure transmitter can ensure long-term stable operation of models such as KYB18G07M1P4C3-I and ZWP-L61-K。If you need the dedicated calibration report template for the EDYBT-4 model or the HB-31C accuracy upgrade solution，please contact our technical engineering team immediately for original factory calibration services for products such as PQ50-GB10CG12M4B and procurement support for MSZ-MSZ11 matching instruments。