Introduction

Pantech Instrument’s Model 902 is an extended version to its predecessor model 901. Model 902 is a Humidity Transmitter + RTD sensing element. The Sensing + Transmitter circuits not only senses the %RH value , but also does convert it into 2-wire 4-20 mA DC signal, for use of the higher instrumentation or controlling layers. The load capacity of this 4-20 mA DC signal is 600 ohms. Model 902 series is often ideally suited for low drain, battery operated systems. The basic HUMIDITY sensor inside the probe gives quality RH ( Relative humidity ) sensing performance in a competitively priced package. The RH sensor is a laser trimmed, thermoset polymer capacitive sensing element with on-chip integrated signal conditioning. The sensing element’s and transmitter PCB’s multilayer construction provides excellent resistance to most application hazards such as wetting, dust, dirt, oils and common environmental chemicals. For TEMPERATURE measurement, a miniature but high quality RTD is installed inside the basic sensor. The model is a fully configurable one, microprocessor based type. The model incorporates low drift operational amplifiers and industrial grade componenets. Burn in of each module ensures a long trouble free operation