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Rotronics® HygroClip™ Temperature and RH Transmitter Calibration Exchange Program

HygroClip Basics:

The Rotronics HygroClip is a digital, temperature and RH transmitter. This transmitter consists of a microprocessor and an ASIC circuit, both of which are located in the probe, along with the capacitive RH sensor and the RTD temperature sensor.

The calibration constants, for both temperature and RH, are stored in the probe itself. The Parameter controller communicates with the HygroClip using a digital format. The Parameter controller does not have the capability to alter the HygroClip data. This means that since the calibration constants are stored in the probe, and since the data is in a digital format, the calibration does not have to be performed on-site. This usually results in a substantial savings in calibration costs. Calibrations can be performed using two methods; full range and full range with verification point(s).

Full Range Calibration*: This involves calibrating the HygroClip transmitter over the entire range of operation. The temperature will be calibrated at a point near the minimum and near the maximum for the particular HygroClip in question.

  • The HygroClip-S sensor will be calibrated at 20°C and 45°C
  • The HygroClip-IC3 or IC1 sensor will be calibrated at 20°C and 85°C

The RH will be calibrated at a constant 25°C, over the normal operational range of the transmitter.

  • The minimum RH will be calibrated at 25°C @ 35%
  • The maximum RH will be calibrated at 25°C @ 80%

*Deviations from the standard full range calibration can be provided. An additional charge may be required. Request a specific quotation from Parameter for details.

Full Range Calibration with Verification Points(s): This involves a full range calibration (as defined above) with additional verifications at specific points per customer request.

The customer can request as many verification points as desired (one temperature and one RH equals a single verification point). The transmitter will be compared to the reference standard at each point and documentation of the temperature and/or RH offset at that point will be provided. No adjustment will be made at the verification point(s). (Each verification point will incur an additional charge.)

Calibration Options

There are several calibration options for the HygroClip, including on-site calibration, reserve sensors and an exchange program.

1.) Reserve Sensors:
A reserve sensor means that the customer will purchase an identical HygroClip transmitter, calibrated to their requirements. These two sensors will be interchanged in order to maintain a calibrated sensor in the system at all times. The sensor that is not in the system will be sent off-site for calibration, as required. The main advantage to this system is that there will always be a spare sensor in case of sensor failure. Parameter has a variety of sensors available – please call for pricing.

2.) Exchange Program:

The Exchange program will allow the customer to receive a reconditioned, calibrated HygroClip transmitter, immediately before the transmitter in their system is due for recalibration. The replacement transmitter is installed in the system and the transmitter in their system is then returned to Parameter as trade-in. (If the removed sensor is not fully functional, an additional replacement cost will be assessed.) Parameter has a variety of sensors available – please call for pricing.


All Parameter calibrations are performed using NIST traceable chilled mirror temperature and dew point sensors.

All Parameter calibrations will include “as-found” and “as-left” data. For the exchange program, the “as-left” data will be referenced to the exchanged sensor, and the “as-found” data will be referenced to the trade-in sensor. In the exchange program, the calibration certificate will be mailed after the trade-in sensor has been evaluated for the “as-found” data.